The study aims to investigate the possible effect of genetic polymorphisms in certain metabolizing enzymes [CYP3A5 * 3 (rs 776746), CYP2C8 * 3 (rs 11572080 and rs 10509681)] and membrane transporters [ABCB1 2677 G>T/A (rs 2032582) and SLC22A1 1222 A > G (rs 628031)] on the plasma level and molecular response (MMR) of imatinib in patients with CML.