UCP-1 plays a key role in thermogenesis through BAT-mediated adaptive non-shivering (Kopecky et al., 1995) and the activation of UCP-1 in WAT can promote beigeing to prevent diet-induced obesity (Schulz and Tseng, 2013; Dempersmier et al., 2015). Here, UCP1 is linked to obesity due to melanocortin 4 receptor deficiency.