When IR occurs in the body, insulin signaling (AKT-GSK signaling pathway, etc.)will be inhibited, which in turn will hinder a series of biological processes such as downstream glycogen synthesis, protein synthesis, glucose transport and anti-lipolysis, leading to the development of metabolic diseases such as obesity, T2D and NAFLD. The gene discussed is AKT1; the disease is obesity due to melanocortin 4 receptor deficiency.