SOD2 and breast cancer: Based on the association of the GPx1 198P→L variant with decreased enzyme activity (13) and the increased risk of bladder and breast cancer due to the combination of the SOD2 Ala/Ala and GPX1 Leu/Leu genotypes (14, 51), we further analyzed association of SOD2 A16V and GPx1 P198L genotype combinations with the risk of PCOS.