Studies have found that certain polymorphisms of the cyclooxygenase-2 gene promoter are associated with an increased risk of breast cancer and a decreased risk of RA.25 26 Also, polymorphisms in the DRB1 gene, the major genetic susceptibility locus for RA,27 have recently been linked to a decreased risk of breast cancer.28 However, because of the complex inheritance, it is difficult to estimate the net effect of such singular genetic factors. Here, PTGS2 is linked to breast carcinoma.