Epistatic interactions between twelve genes such as ABCA1, APOC1, CETP, F2, GALNT2, NPC1L1, PLTP, ST3GAL4, STARD3, ZNF648, SCARB1, and PPP1R3B were established to impact the levels of high density lipoprotein cholesterol in plasma of CAD patients. The gene discussed is APOC1; the disease is coronary artery disorder.