GSTM1 and polycystic ovary syndrome: Furthermore, there was a protective effect observed with the combinations of GSTT1 (+) GSTM1 (−) and GSTT1 (−) GSTM1 (+), as well as both null genotypes in relation to PCOS patients, with an OR of 0.41 (0.19 to 0.93) and RR of 0.62 (0.42 to 0.94), yielding a significance level of p < 0.003.