The effects of ovariectomy, nonsteroidal antiestrogens, such as tamoxifen, or aromatase inhibitors on the early stages of PyMT carcinogenesis do not appear to have been reported, but would be of considerable interest in the context of breast cancer chemoprevention, as would their potential for suppressing the stimulatory action of obesity/inflammation. Here, CYP19A1 is linked to breast cancer.