Description of the Variability of Drug Transporter Database (VARIDT)

Drug transporters (DTs) are acknowledged as important determinants governing drug absorption, excretion, and, in many cases, extent of drug entry into target organs (Annu Rev Pharmacol Toxicol. 2012, 52: 249-73). The variability of DTs has thus attracted considerable attentions and broad interests (Nat Rev Drug Discov. 2015, 14: 29-44; Clin Pharmacol Ther. 2019, doi: 10.1002/cpt.1373; Ann Oncol. 2013, 24: 1513-25). There are three aspects of variability: (1) epigenetic regulations and genetic polymorphisms of DTs playing key role in drug resistance (Sci Transl Med. 2016, 8: 348ra97) and clinical treatment optimization (Adv Drug Deliv Rev. 2017, 116: 21-36); (2) species-, tissue-, and disease-specific abundances of DT proteins essential for bridging preclinical study with clinical trial (Mol Pharm. 2015, 12: 4259-69), balancing efficacy and safety (Sci Transl Med. 2016, 8: 352ra109), and predicting disease-drug interaction (Clin Pharmacol Ther. 2018, 104: 900-15), respectively; (3) exogenous factors modulating activity of DTs and leading to the altered disposition of natural substrates and the transported drugs (Adv Drug Deliv Rev. 2015, 86: 17-26; Clin Pharmacol Ther. 2016, 100: 259-67). These variability data are vital for the clinical studies, and the accumulation of such data can lay the foundation for big data-driven precision medicine.

Moreover, due to the extreme complexity of drug dispositions in living organisms, the interplays among different aspects of DT variability have recently emerged to be a new promising research direction of high-impact studies (Drug Resist Updat. 2017, 32: 23-46; Cancer Lett. 2016, 370: 153-64). Particularly, one of the common mechanisms of the cancer multidrug resistance (MDR) is the overexpression of the particular DTs in cancer cells (Cancer Lett. 2016, 370: 153-64), and the developments of exogenous chemical to inhibit the efflux of these DTs are successfully proposed to reverse caner MDR (Drug Resist Updat. 2017, 32: 23-46; Cancer Lett. 2016, 370: 153-64). These and other potential studies require the collectively analyses of multiple data among different aspects of DT variability. However, no database has been available so far to provide the comprehensive information of all aspects of DT variability.

Therefore, the Variability of Drug Transporter Database (VARIDT) was introduced. First, a comprehensive literature review on all drugs approved by U.S. FDA and >1,000 drugs in clinical trial or preclinical research was conducted. Different from the small amount of DTs (~20) well characterized in previous work (Nat Rev Drug Discov. 2010, 9: 215-36), 177 DTs were confirmed for the first time in VARIDT to transport approved drug(s) and 146 DTs were to transport the drug(s) in clinical/preclinical test. Second, for these hundreds of newly confirmed DTs, the VARIDT not only comprehensively provided all three aspect of their variability data but also allowed the mutual connection (interplay) between any two aspects. All in all, the VARIDT is UNIQUE in (1) covering the largest number of DTs confirmed by their corresponding drugs among available knowledge bases, (2) providing for the first time the comprehensive sets of DT variability data, and (3) allowing the interplay analysis among different aspects of DT variability. All diseases in VARIDT were standardized using the latest revision of International Classification of Diseases (ICD-11) to serve comprehensive health management, and the vast majority (~80%) of the confirmed DTs in VARIDT had the data from multiple aspects of variability, which allowed interplays among these aspects. All data are FULLY DOWNLOADABLE .

Identify Drug Transporter Entries by Whole Database Search

Users can identify drug transporter (DT) entry by searching transporter gene name, transporter protein name, transporter family name, transported drug name, disease/disease class name of the transported drug, International Classification of Diseases (ICD) code, and so on among the entire textual component of VARIDT. DT information can be accessed via crosslink to UniProtKB, TCDB and Gene Database from the resulting webpage. Query can be submitted by entering keywords into the main searching frame. Users can specify part/full DT name, drug name or any other DT-related information in the text field. Moreover, user can search by put DT, drug or other information together into the text field (separated by space or tab) for narrowing the output results. To facilitate a more customized input query, the wild characters of "*" and "?" are fully supported in VARIDT. For example:

1. If search: "P-glycoprotein 1", finds only entry with DT name "P-glycoprotein 1"

2. If search: "Oxaliplatin", finds four entries of DTs transporting the drug "Oxaliplatin"

3. If search: "Lung cancer", finds various entries of DTs transporting "lung cancer" drugs

4. If search: "Multidrug and toxin extrusion protein?", finds DT entries named as "Multidrug and toxin extrusion protein 1" and "Multidrug and toxin extrusion protein 2". Here, "?" represents any one character

5. If search: "Multidrug and toxin *", finds the same entries as above. Here "*" represents a string of any length. In this case, it represents "extrusion protein 1" and "extrusion protein 2".


For example, if you want to know the detail information of organic anion transporter 1 (SLC22A6), you can search it's transporter information by searching "organic anion transporter 1 (SLC22A6)" in the "Search for Drug Transporter Entries:" field of home page or selecting "OAT1: Organic anion transporter 1" in the "Search Drug Transporter by Transporter Name:" drop-down list.

Search "organic anion transporter 1 (SLC22A6)" in the "Search for Drug Transporter Entries:" field.


Alternatively, select "OAT1: Organic anion transporter 1" in the "Search Drug Transporter by Transporter Name:" drop-down list.


Search result list of transporter with transporter information, the Transporter Info button links to Drug Transporter (DT) Information page and the Drug Info button links to the Representative Drug Information.


Drug Transporter (DT) Information page, "General Information and Variability Data of DT" section display the general information of OAT1 and 10 representative diseases related with OAT1.


The blue blocks below Disease Block display 3 aspects of variability data of OAT1 along with the hyperlink to Epigenetic Regulations of DT (ERD), Genetic Polymorphisms of DT (GPD), Disease-specific Protein Abundances of DT (DPAD), Species/Tissue-specific Protein Abundances of DT (S/TPAD) and Exogenous Factors (drugs, dietary constituents, natural products, etc.) Modulating DT Activity (EFMDA).


The brief information (drug name, indication and highest status) of drugs which were transported by OAT1 was displayed below Variability Block and the drugs were classified by its highest status. The Drug Info button links to the drug information in more detail.


"Drug-DT Affinity Assessed by Cell Line" section display the drugs with drug-DT affinity data, which is constructed by drug name, cell line and Km value.

Identify Drug Transporter Entries by Selecting DT Name/Family/Drug Name/Disease Class

Users can identify DT entry among the entire textual component of VARIDT by selecting a DT name, DT family name, transported drug name or ICD-11 defined disease class name from the corresponding drop-down lists. (a) The drop-down list of DT name (gene name: DT protein name) contains 266 DTs that are confirmed by at least one drug transported by these DTs; (b) The drop-down list of DT family name (family full name (abbreviation)) contains 38 protein families that are occupied by all DTs; (c) The drop-down list of transported drug name contains 585 approved drugs and 246 drugs in clinical/preclinical studies; (d) The drop-down list of ICD-11 defined disease class (ICD-11 code: disease class name) contains 142 distinct disease classes. To accelerate the DT identification process, all these drop-down lists are alphabetically sorted (A-Z). Contrary to the field of "Search for Drug Transporter Entries", these drop-down lists search the keyword by the EXACT matching instead of the fuzzy one.

Identify the Transported Drug Entries by Whole Database Search

Users can identify the transported drug entry by searching drug name, disease/disease class name of the transported drug, International Classification of Diseases (ICD) code, transporter gene name, transporter protein name, transporter family name, and so on among the entire textual component of VARIDT. The transported drug information can be accessed via crosslink to PubChem, ChEBI and TTD from the resulting webpage. Query can be submitted by entering keywords into the main searching frame. Users can specify part/full drug name, DT name or any other related information in the text field. Moreover, user can search by put drug, DT or other information together into the text field (separated by space or tab) for narrowing the output results. To facilitate a more customized input query, the wild characters of "*" and "?" are fully supported in VARIDT. For example:

1. If search: "Methotrexate", finds only entry with drug name "Methotrexate"

2. If search: "MATE2", finds ten entries of drugs transported by the DT "MATE2"

3. If search: "Influenza", finds three entries of drugs for treating the disease "Influenza"

4. If search: "Multidrug and toxin extrusion protein?", finds a variety of drug entries transported by the DTs named as "Multidrug and toxin extrusion protein 1" and "Multidrug and toxin extrusion protein 2". Here, "?" represents any one character

5. If search: "Multidrug and toxin *", finds the same entries as above. Here "*" represents a string of any length. In this case, it represents "extrusion protein 1" and "extrusion protein 2".


For example, if you want to know the detail information of Methotrexate, you can search it by searching "Methotrexate" in the "Search for Drug Entries:" field of home page or selecting "Methotrexate" in the "Search Drug by Drug Name:" drop-down list.

Search "Methotrexate" in the "Search for Drug Entries:" field.


Alternatively, select "Methotrexate" in the "Search Drug by Drug Name:" drop-down list.


Search result list of drugs with drug information, a thumbmail of drug structure and a brief introduction of drug was provied and the Drug Info button links to the Drug Information page.


Drug Information page, "General Information" section display the general information of Methotrexate including its name, indication, structure, formula canonical SMILES, pharmaceutical properties and so on.


Cross-matching ID between VARIDT drugs and other public databases (PubChem, ChEBI, TTD) was displayed following the general information block. And the external links to these public databases was also provided.


The "DT(s) Transporting This Drug" block showed the brief information of all the transporters which were capable of transporting Methotrexate. The detail information could be viewed by clicking the Transporter Info button.


The "Drug-Transporter Activity Data" section displayed all the activity data we could find, which quantified Methotrexate's affinity to its transporters and was contructed by Km value and cell line.

Identify Drug Entries by Selecting Drug Name/Disease Class/DT Name/Family

Users can identify drug entry among the entire textual component of VARIDT by selecting a transported drug name, ICD-11 defined disease class name, DT name or DT family name from the corresponding drop-down lists. (a) The drop-down list of transported drug name contains 585 approved drugs and 246 drugs in clinical/preclinical studies; (b) The drop-down list of ICD-11 defined disease class (ICD-11 code: disease class name) contains 142 distinct disease classes; (c) The drop-down list of DT name (gene name: DT protein name) contains 266 DTs that are confirmed by at least one drug transported by these DTs; (d) The drop-down list of DT family name (family full name (abbreviation)) contains 38 protein families that are occupied by all DTs. To accelerate the drug identification process, all these drop-down lists are alphabetically sorted (A-Z). Contrary to the field of "Search for Drug Entries", these drop-down lists search the keyword by the EXACT matching instead of the fuzzy one.

Identify the Epigenetic Regulations of DT (ERD) Entries by Whole Database Search

Users can identify the ERD entry by searching drug name, disease/disease class name of the transported drug, International Classification of Diseases (ICD) code, transporter gene name, transporter protein name, transporter family name, and so on among the entire textual component of VARIDT. Query can be submitted by entering keywords into the main searching frame. Users can specify part/full drug name, DT name or any other related information in the text field. Moreover, user can search by put drug, DT or other information together into text field (separated by space or tab) for narrowing output results. To facilitate a more customized input query, the wild characters of "*" and "?" are fully supported in VARIDT. For example:

1. If search: "ABCG2", finds only ERD entry with DT name "ABCG2"

2. If search: "Oxaliplatin", finds three ERD entries of three DTs transporting "Oxaliplatin"

3. If search: "Influenza", finds six ERD entries of six DTs transporting "Influenza" drugs

4. If search: "Multidrug and toxin extrusion protein?", finds ERD entry of the DT "Multidrug and toxin extrusion protein 1". Here, "?" represents any one character

5. If search: "Multidrug and toxin *", finds the same entry as above. Here "*" represents a string of any length. In this case, it represents "extrusion protein 1".

Identify ERD Entries by Selecting DT Name/Family/Disease Class

Users can identify ERD entry among the entire textual component of VARIDT by selecting a DT name, DT family name, or ICD-11 defined disease class name from the corresponding drop-down lists. (a) The drop-down list of DT name (gene name: DT protein name) contains 266 DTs that are confirmed by at least one drug transported by these DTs; (b) The drop-down list of DT family name (family full name (abbreviation)) contains 38 protein families that are occupied by all DTs; (c) The drop-down list of ICD-11 defined disease class (ICD-11 code: disease class name) contains 142 distinct disease classes. To accelerate the ERD identification process, these drop-down lists are alphabetically sorted (A-Z). Contrary to the field of "Search for the Epigenetic Regulations of Drug Transporter (ERD)", these drop-down lists search the keyword by the EXACT matching instead of the fuzzy one.

Identify the Genetic Polymorphisms of DT (GPD) Entries by Whole Database Search

Users can identify the GPD entry by searching drug name, disease/disease class name of the transported drug, International Classification of Diseases (ICD) code, transporter gene name, transporter protein name, transporter family name, and so on among the entire textual component of VARIDT. Query can be submitted by entering keywords into the main searching frame. Users can specify part/full drug name, DT name or any other related information in the text field. Moreover, user can search by put drug, DT or other information together into text field (separated by space or tab) for narrowing output results. To facilitate a more customized input query, the wild characters of "*" and "?" are fully supported in VARIDT. For example:

1. If search: "ABCB1", finds only GPD entry with DT name "ABCB1"

2. If search: "Oxaliplatin", finds four GPD entries of four DTs transporting "Oxaliplatin"

3. If search: "Influenza", finds five GPD entries of five DTs transporting "Influenza" drugs

4. If search: "Multidrug and toxin extrusion protein?", finds two GPD entries of two DTs named as "Multidrug and toxin extrusion protein 1" and "Multidrug and toxin extrusion protein 2". Here, "?" represents any one character

5. If search: "Multidrug and toxin *", finds the same entries as above. Here "*" represents a string of any length. In this case, it represents "extrusion protein 1" and "extrusion protein 2".

Identify GPD Entries by Selecting DT Name/Family/Disease Class

Users can identify GPD entry among the entire textual component of VARIDT by selecting a DT name, DT family name, or ICD-11 defined disease class name from the corresponding drop-down lists. (a) The drop-down list of DT name (gene name: DT protein name) contains 266 DTs that are confirmed by at least one drug transported by these DTs; (b) The drop-down list of DT family name (family full name (abbreviation)) contains 38 protein families that are occupied by all DTs; (c) The drop-down list of ICD-11 defined disease class (ICD-11 code: disease class name) contains 142 distinct disease classes. To accelerate the GPD identification process, these drop-down lists are alphabetically sorted (A-Z). Contrary to the field of "Search for the Genetic Polymorphisms of Drug Transporter (GPD)", these drop-down lists search the keyword by the EXACT matching instead of the fuzzy one.

Search the Disease-specific Protein Abundances of DT (DPAD) Entries

Users can identify the DPAD entry by searching drug name, disease/disease class name of the transported drug, International Classification of Diseases (ICD) code, transporter gene name, transporter protein name, transporter family name, and so on among the entire textual component of VARIDT. Query can be submitted by entering keywords into the main searching frame. Users can specify part/full drug name, DT name or any other related information in the text field. Moreover, user can search by put drug, DT or other information together into text field (separated by space or tab) for narrowing output results. To facilitate a more customized input query, the wild characters of "*" and "?" are fully supported in VARIDT. For example:

1. If search: "ABCG2", finds only DPAD entry with DT name "ABCG2"

2. If search: "Oxaliplatin", finds four DPAD entries of four DTs transporting "Oxaliplatin"

3. If search: "Influenza", finds five DPAD entries of five DTs transporting "Influenza" drugs

4. If search: "Multidrug and toxin extrusion protein?", finds DPAD entry of the DT "Multidrug and toxin extrusion protein 1". Here, "?" represents any one character

5. If search: "Multidrug and toxin *", finds the same entry as above. Here "*" represents a string of any length. In this case, it represents "extrusion protein 1".

Identify DPAD Entries by Selecting DT Name/Family/Disease Class

Users can identify DPAD entry among the entire textual component of VARIDT by selecting a DT name, DT family name, or ICD-11 defined disease class name from the corresponding drop-down lists. (a) The drop-down list of DT name (gene name: DT protein name) contains 266 DTs that are confirmed by at least one drug transported by these DTs; (b) The drop-down list of DT family name (family full name (abbreviation)) contains 38 protein families that are occupied by all DTs; (c) The drop-down list of ICD-11 defined disease class (ICD-11 code: disease class name) contains 142 distinct disease classes. To accelerate the DPAD identification process, these drop-down lists are alphabetically sorted (A-Z). Contrary to the field of "Search for Disease-specific Protein Abundances of Drug Transporter (DPAD)", these drop-down lists search the keyword by the EXACT matching instead of the fuzzy one.

Search the Species/Tissue-specific Protein Abundances of DT (S/TPAD) Entries

Users can identify the S/TPAD entry by searching drug name, disease/disease class name of the transported drug, International Classification of Diseases (ICD) code, transporter gene name, transporter protein name, transporter family name, and so on among the entire textual component of VARIDT. Query can be submitted by entering keywords into the main searching frame. Users can specify part/full drug name, DT name or any other related information in the text field. Moreover, user can search by put drug, DT or other information together into text field (separated by space or tab) for narrowing output results. To facilitate a more customized input query, the wild characters of "*" and "?" are fully supported in VARIDT. For example:

1. If search: "ABCB1", finds only S/TPAD entry with DT name "ABCB1"

2. If search: "Oxaliplatin", finds four S/TPAD entries of four DTs transporting "Oxaliplatin"

3. If search: "Influenza", finds five S/TPAD entries of five DTs transporting "Influenza" drugs

4. If search: "Multidrug and toxin extrusion protein?", finds S/TPAD entry of the DT "Multidrug and toxin extrusion protein 1". Here, "?" represents any one character

5. If search: "Multidrug and toxin *", finds the same entry as above. Here "*" represents a string of any length. In this case, it represents "extrusion protein 1".

Identify S/TPAD Entries by Selecting DT Name/Family/Disease Class

Users can identify S/TPAD entry among the entire textual component of VARIDT by selecting a DT name, DT family name, or ICD-11 defined disease class name from the corresponding drop-down lists. (a) The drop-down list of DT name (gene name: DT protein name) contains 266 DTs that are confirmed by at least one drug transported by these DTs; (b) The drop-down list of DT family name (family full name (abbreviation)) contains 38 protein families that are occupied by all DTs; (c) The drop-down list of ICD-11 defined disease class (ICD-11 code: disease class name) contains 142 distinct disease classes. To accelerate the S/TPAD identification process, these drop-down lists are alphabetically sorted (A-Z). Contrary to the field of "Search for Species/Tissue-specific Protein Abundances of Drug Transporter (S/TPAD)", these drop-down lists search the keyword by the EXACT matching instead of the fuzzy one.

Search the Entries of DT Modulated by Exogenous Factor (DTMEF)

Users can identify the DTMEF entry by searching exogenous factor name, drug name, disease/disease class name of the transported drug, International Classification of Diseases (ICD) code, transporter gene name, transporter protein name, transporter family name, and so on among the entire textual component of VARIDT. Query can be submitted by entering keywords into the main searching frame. Users can specify part/full drug name, DT name or any other related information in the text field. Moreover, user can search by put drug, DT or other information together into text field (separated by space or tab) for narrowing output results. To facilitate a more customized input query, the wild characters of "*" and "?" are fully supported in VARIDT. For example:

1. If search: "Cigarette smoke condensate", finds nine DTMEF entries of nine DTs modulated by "Cigarette smoke condensate"

2. If search: "ABCG2", finds only DTMEF entry with DT name "ABCG2"

3. If search: "Oxaliplatin", finds three DTMEF entries of three DTs transporting "Oxaliplatin"

4. If search: "Influenza", finds five DTMEF entries of five DTs transporting "Influenza" drugs

5. If search: "Multidrug and toxin extrusion protein?", finds two DTMEF entries of two DTs named as "Multidrug and toxin extrusion protein 1" and "Multidrug and toxin extrusion protein 2". Here, "?" represents any one character

6. If search: "Multidrug and toxin *", finds the same entries as above. Here "*" represents a string of any length. In this case, it represents "extrusion protein 1" and "extrusion protein 2".

Identify DTMEF Entries by Selecting Exogenous Factor/DT Name/Family

Users can identify DTMEF entry among the entire textual component of VARIDT by selecting a exogenous factor name, DT name, or DT family name from the corresponding drop-down lists. (a) The drop-down list of exogenous factor name contains 1,225 distinct exogenous factors; (b) The drop-down list of DT name (gene name: DT protein name) contains 266 DTs that are confirmed by at least one drug transported by these DTs; (c) The drop-down list of DT family name (family full name (abbreviation)) contains 38 protein families that are occupied by all DTs. To accelerate the DTMEF identification process, these drop-down lists are alphabetically sorted (A-Z). Contrary to the field of "Search for Drug Transporter(s) Modulated by Exogenous Factor (DTMEF)", these drop-down lists search the keyword by the EXACT matching instead of the fuzzy one.

Download the Full Data of VARIDT from a Variety of Customized Links

VARIDT provides functions for downloading all VARIDR data from various customized links.

(1) full DT variability data (epigenetic regulation data of DTs, genetic polymorphism data of DTs, disease-specific protein abundances of DTs, species-specific protein abundances of DTs, tissue-specific protein abundances of DTs and exogenous factors altering DT activity)

(2) full sequence/structure/function data (sequence and structure data of DTs, transporter-drug affinity data based on cell line experiment, functional family data for each DT, 2D structure data for the drugs transported by DTs, 3D structure data for the drugs transported by DTs, SMILES and InChI for the drugs transported by DTs and therapeutic classes and physicochemical properties for the drugs)

(3) synonyms and cross-matching data (cross-matching ID between the DTs and a variety of public databases, synonyms of DTs and their corresponding drugs, DTs to disease mapping with ICD identifiers and Drug to disease mapping with ICD-11 identifiers)

All data can be readily downloaded by simply clicking the corresponding 'Click to Save' button.

If you find any error in data or bug in web service, please kindly report it to Dr. Yin and Dr. Li.