GPX1 and polycystic ovary syndrome: Because GPx1 and CAT are important intracellular antioxidant enzymes and play an important role in maintaining the dynamic balance of oxidative stress interacting with SOD2 (26, 27), we hypothesized that the functional SNPs, the P198L in GPx1 gene and the C-262T in CAT gene, may be associated with PCOS.