More specifically Masp1, Tef, Rtn2 and Ube2l3 showed contrasting expression patterns before and after gastric bypass (Fig. 6B) but the effects were statistically significant for Tef only, which highlights a possible specific role of Tef in obesity and IR of obese patients. The gene discussed is UBE2L3; the disease is obesity due to melanocortin 4 receptor deficiency.