ESR1 and breast cancer: We hypothesize that independently of menopausal status (1) relative E2 and cortisol breast adipose tissue amounts as well as the ratio E2:E1 and cortisol on cortisone are increased with adiposity; (2) worst clinical breast cancer features, such as tumor stage, size and grade are associated with lower relative adipose tissue steroid amounts; and (3) relative estrogen amounts are increased in women with ER+/PR+ tumors.