GSR and breast cancer: In the present study, we wanted to extend these findings with polymorphisms in the antioxidant genes SOD1 (encoding SOD), CAT (encoding CAT) and GSR (encoding GR) in a study group of 975 postmenopausal women with BC and 975 matched controls nested within the DCH cohort; and search for gene-environment interactions between the polymorphisms, enzyme activities and intake of fruits and vegetables, alcohol and smoking in relation to BC risk.