During preadipocyte differentiation, the expression of peroxisome proliferator-activated receptor gamma (PPARγ) and fatty acid binding protein 4 (FABP4) and the elevated expression of lipogenic factors, such as lysophosphatidic acid acyltransferase theta (LPAATθ), Lipin 1, and fatty acid synthase (FAS), lead to increased lipid accumulation and the development of obesity [13]. The gene discussed is FABP4; the disease is obesity due to melanocortin 4 receptor deficiency.