PPIG and polycystic ovary syndrome: Although some of the CYP genes we were reviewing in this research have not been repeatedly associated with PCOS and infertility clinical manifestations, some of them have been repeatedly associated with previously mentioned disease symptoms in different populations: (1) CYP17A1: rs743572 in Chile [65], India [46,58,72], Iraq [67], Iran [70], and Pakistan [71]; (2) CYP19A1: tetranucleotide allele with 7 repeats (TTTA)7 in Greece [94,96], rs2470152 in China [95], and India [107], and rs2414096 in Iran [99], Egypt [109], and Iraq [66].