Although Htr3a KO mice showed reduced weight gain in HFD-induced obesity model, their WAT did not show remarkable differences in fat mass and histology compared with WAT of WT littermates (Figs 7a,b and 8e), suggesting that insulin resistance of Htr3a-null WAT was comparable to WT WAT. Here, HTR3A is linked to obesity due to melanocortin 4 receptor deficiency.