A subject carrying the variants CYP1A1 Val/Val or CYP1A1 Ile/Val in association with GSTM-null genotype has a 6.90-fold higher risk for infertility than a subject carrying CYP1A1 Ile/Ile in association with a GSTM1 wild-type genotype [37]. Here, GSTM1 is linked to Infertility.