We considered the three most connective nodes as hub-bottleneck genes: prostaglandin-endoperoxide synthase 2 ( PTGS2 ), tumor necrosis factor α-induced protein 3 ( TNFAIP3 ), and F-box and leucine rich repeat protein 20 ( FBXL20 ), which might play a critical role in obesity. The gene discussed is PTGS2; the disease is obesity due to melanocortin 4 receptor deficiency.