Hyperinsulinemia has been discussed as a potential mediator of obesity-related cancer growth: activating mutations in the PI3K/Akt pathway are common (10–30% incidence) and confer a poorer prognosis in humans with colon cancer [54, 55], breast cancer [56, 57], and prostate cancer [58, 59]. Here, AKT1 is linked to obesity due to melanocortin 4 receptor deficiency.