CYP19A1 and obesity due to melanocortin 4 receptor deficiency: Three observations explain this: i) in FBC, HMG-CoAR expression was positively associated with overweight18, ii) in turn, obesity was designed as a risk factor for MBC as a consequence of the age-related increase in both aromatase activity and fat mass, which lead to an excess of estrogens11, 34, 35, 36, and iii) molecular studies documented intratumoral aromatase expression and elevated levels of 17β-estradiol in MBC tissues37, 38, and both these observations may be connected with intratumoral activation of the mevalonate pathway.