SMAD3 and obesity due to melanocortin 4 receptor deficiency: In addition, we found that deletion of Smad3 in db/db mice protected against the development of hyperglycaemia (Figure 1B), obesity (Figure 1C, Figure S1A-C), glucose intolerance (Figure 1D) and insulin resistance (Figure 1E), while the normalised food intake was not significantly altered in Smad3 KO-db/db mice (Figure S1D).