Adipocyte differentiation, a critical event in the progression of obesity, is an intricate process tightly controlled by various transcription factors, including the members of the CCAAT/enhancer binding protein (C/EBP) family and peroxisome proliferator-activated receptor γ (PPARγ) [10,11]. The gene discussed is PPARG; the disease is obesity due to melanocortin 4 receptor deficiency.