UCP1 and obesity due to melanocortin 4 receptor deficiency: Although the IBAT depot under these conditions would normally only represent ∼45% of the thermogenic capacity of brown adipose tissue, the virtual absence of effect of the IBAT denervation on the development of body weight/obesity in HFD-fed mice (Figs. 1C and 4A) could imply that hyper-recruitment of other BAT or WAT depots compensated for the absence of increased UCP1 amounts in IBAT.