The GSTP1 G/A single nucleotide polymorphism caused valine (Val) took the place of isoleucine (Ile) at codon 105, resulting in decreased enzymatic activity and low ability to metabolize certain xenobiotics and carcinogens.[39] Biochemical studies indicated that the GSTP1 AA genotype was 2 to 3 times less stable[40] and might be associated with the risk of gynecological cancer. The gene discussed is GSTP1; the disease is female reproductive organ cancer.