TGF-β signalling is also linked to adiposity through the regulation of adipocyte differentiation and oxidative metabolism (Zamani and Brown, 2011), and TGFB1 is overexpressed in obesity (Samad et al, 1997; Fain et al, 2005). This evidence concerns the gene TGFB1 and obesity due to melanocortin 4 receptor deficiency.