Drug-gene sets were created using Drug Targetor,19 which collates information across a range of drug-gene databases, including ChEMBL, PHAROS, PDSP Ki database and NCBI PubChem BioAssay. We grouped drug-gene sets into two hierarchical levels based on the Anatomical Therapeutic Chemical (ATC) Classification System: pharmacological subgroup (3rd level) and chemical subgroup (4th level).