If true, possible reasons why this would be true include: (1) 80% of all MBS performed in the U.S. occur in women, making an effect of MBS, should it exist, easier to detect [33]; and (2) the most consistent beneficial effects in women’s cancers are in postmenopausal breast and endometrium, suggesting that the downregulation of aromatase and subsequent estrogen production driving these cancers in obese subjects was downregulated with weight loss. Here, CYP19A1 is linked to cancer.