Results of published meta-analysis literature reviews on the prevalence of GSTM1 and GSTT1 genes polymorphisms have shown that GSTM1 and GSTT1 null genotypes are associated with a strong and modest increase in the risk of male infertility respectively; dual null genotype of GSTM1/GSTT1 is also significantly associated with increased risk of male idiopathic infertility (81, 82). Here, GSTM1 is linked to male infertility.