In obesity, increased TGF-β signalling has been suggested to exert pro-fibrogenic actions by stimulating the expression of tissue inhibitors of metalloproteases (TIMPs), including TIMP-1, TIMP-3, and TIMP-4, and connective tissue growth factor (CTGF) [55, 87]. The gene discussed is TIMP3; the disease is obesity due to melanocortin 4 receptor deficiency.