NQO1 SNP rs1800566 is a c.558C >T missense variant in exon 6 of the NQO1 gene which causes the substitution of proline for serine (P > S), leading to a reduction in the activity of NQO1 enzyme in C/T heterozygotes while causing a NQO1 inactivity in T/T homozygotes [38,39,40] resulting in an increased risk of ovarian cancer. This evidence concerns the gene NQO1 and ovarian cancer.