In the interest of the readers and audience in obesity and diabetes research, I would like to take this opportunity to highlight some of the differences in the models used by Dietzsch et al.1 and Chhabra et al.2:Dietzsch et al. used constitutive Adgrl1 knockout mice throughout their study. This evidence concerns the gene ADGRL1 and obesity due to melanocortin 4 receptor deficiency.