Consistent with reduced obesity, HFD‐fed Cxxc5−/− mice exhibited markedly improved glucose tolerance and insulin sensitivity (Figure 2C–E), with improved levels of metabolic parameters, including leptin, resistin, adiponectin, TGs, total cholesterol and HDL‐cholesterol levels (Figure S4). The gene discussed is INS; the disease is obesity due to melanocortin 4 receptor deficiency.