A: PCR-RFLP product for OCT1 (rs628031) gene polymorphism (Lane M: 100 bp ladder; Lane 1-lane 5, 8, 10, 13 and 14: WT, 422 bp; Lane 7,9,11,12, and 13: HT, 422 bp, 268 bp and 154 bp; Lane 6: MT, 268 bp and 154 bp). B: PCR-RFLP product for OCT3 (rs3088442) gene polymorphism (Lane L: 100 bp ladder; Lane 1–5 and 7: WT, 104 bp and 57 bp; Lane 10, 14 and 15: HT, 171 bp, 104 bp and 67 bp; Lane 6, 8, 9, 11 and 16: MT, 171 bp). C: PCR-RFLP product for OCT2 (rs145450955) gene polymorphism (Lane L: 100 bp ladder, Lane 3: WT, 331 bp; Lane 13: HT, 331 bp, 218 bp and 113 bp; Lane 1,2,4–12, and 14: MT, 218 bp and 113 bp). D: PCR-RFLP product for OCT3 (rs2292334) gene polymorphism (Lane L: 100 bp ladder; Lane 2, 6–10: WT, 237 bp and 70 bp; Lane 1, and 3, HT, 307 bp, 237 bp and 70 bp; Lane 4 and 5: MT, 307 bp).