Also similar to endometrial cancer, the homozygous deletion of GSTM1 was nominally statistically significantly associated with a reduced risk of ovarian cancer, and the homozygous deletion of GSTT1 was statistically non-significantly associated [among all women: HR: 0.59 (0.18–1.95); never-smokers: HR: 0.58 (0.13–2.55)] with a reduced risk of ovarian cancer. This evidence concerns the gene GSTM1 and ovarian carcinoma.