GSTP1 and Infertility: Genotyping analysis of GSTM1, GSTT1, and GSTP1 genes polymorphisms for the first time showed that combination of deletion genotypes of GST (GSTM1 and GSTT1) and of GSTM1 null, GSTT1 null, and GSTP1 (Ile/Ile) genotypes pose an even higher risk of infertility, but the non-deletion GSTM1 and GSTT1 genotypes and the variant genotypes of GSTP1 (Ile/Val and Val/Val) have emerged as protective factors.