The body weight gain of CKO‐normal diet (ND) mice from 6 to 30 weeks was much lower than that of WT‐ND, but the body weight gain of CKO‐HFD mice was higher than WT‐HFD suggesting that Wfs1 deficiency increased the susceptibility to HFD‐inducing obesity (Figure 1H). Here, WFS1 is linked to obesity due to melanocortin 4 receptor deficiency.