INS and obesity due to melanocortin 4 receptor deficiency: Hyperinsulinemia has emerged as a focal point of research on obesity-related tumors, with increased plasma insulin concentrations independently predicting increased risk and mortality in prostate [1, 2], colon [3–7], breast [8–13], endometrial [12, 14, 15], and pancreatic cancer [16, 17], as well as several other tumor types.