It is thought that insulin resistance (IR) is an important mechanism linking obesity to the development of T2D, and recent integration of longitudinal data on IR, pubertal timing, age, sex, adiposity, and levels of the hormone Insulin-like growth factor-1(IGF-1) has highlighted a strong and gender-specific relationship between adiposity and IR in childhood2. The gene discussed is IGF1; the disease is obesity due to melanocortin 4 receptor deficiency.