PTGS1 and breast cancer: Aspirin (an irreversible inhibitor of both cyclooxygenase 1 and 2 (COX‐1 and COX‐2) has also been proposed as a putative chemopreventative agent in the breast cancer (BC) setting, where COX‐2 has been shown to expressed in up to 40% of BCs,2 and is associated with larger tumour size, higher histological staged tumours, negative hormone receptor status, a high proliferation rate, and HER2 amplification.3