NQO1 and breast cancer: Comparison of our data on the P187S polymorphism in NQO1 with those in the literature shows inconsistency (Hamajima et al, 2002; Siegelmann-Danieli and Buetow, 2002), particularly with the one from Japan where the frequency for the 187S homozygotes was 16.5% in the controls and 14.3% in the breast cancer patients group.