SLC22A2 (OCT2) is an organic cation transporter abundantly expressed in kidney tissue that facilitates bidirectional transport of endogenous and exogenous cationic compounds 1. As a member of the SLC22 transporter family, SLC22A2 plays a pivotal role in drug disposition and regulates key metabolic pathways and signaling molecules 2. The transporter mediates cellular uptake of pharmacologically important drugs including metformin, cisplatin, cimetidine, and lamivudine, with isoform-specific substrate selectivity differences 1. SLC22A2 genetic polymorphisms significantly influence individual drug response and toxicity. Variants rs316019 and rs316009 associate with increased metformin adverse drug reactions (7.3-fold higher odds for homozygous carriers) 3, while rs316019 also associates with oxaliplatin-induced hematological toxicity severity 4. Promoter haplotypes show ethnicity-specific variation; African-specific haplotypes decrease gene expression and potentially alter pharmacokinetic profiles 1. Functionally, SLC22A2 inhibition by compounds like carvedilol and cimetidine reduces cisplatin accumulation in renal tissues, alleviating nephrotoxicity without compromising anti-tumor efficacy 5. Additionally, dolutegravir's inhibition of SLC22A2-mediated creatinine secretion causes a predictable 10-14% serum creatinine increase without affecting true glomerular filtration 6. These findings highlight SLC22A2's importance as a pharmacogenomic biomarker for precision medicine applications.