PPARG and obesity due to melanocortin 4 receptor deficiency: In addition to mimicking human Prader–Willi syndrome or bdelygmia by affecting the regulatory centers of feeding behavior, we can assess metabolism-related genes, such as peroxisome proliferator-activated receptor gamma [66], diacylglycerol O-acyltransferase 2 [67], and CCAAT enhancer-binding protein alpha [68], and simulate and investigate obesity induced by various factors by overexpressing or knocking out genes in AgRP neurons to identify effective strategies to maintain health, through methods such as drug screening and gene therapy.