AR and breast cancer: The CAG repeats of the breast cancer samples were compared with those of similarly-aged healthy controls, and women with two long AR alleles (≥21 CAG repeats) were found to possess an increased risk of breast cancer, while those with two short AR alleles (<21 CAG repeats) were likely to be normal (p = 0.00069; 95% confidence interval 0.5 ~ −0.13).