Polymorphisms: GSTO1*A140D (C419A; rs4925), GSTO2*N142D (A424G; rs156697)Main findings: - association of GSTO1*A140D polymorphism with HCC, cholangiocarcinoma, and breast cancer;- no significant association of GSTO1*A140D polymorphism and colorectal cancer; - no significant association of GSTO2*N142D polymorphism with any type of cancer. The gene discussed is GSTO2; the disease is cholangiocarcinoma.