Pgc1, on the other hand, in addition to being the main regulator of Ucp1-mediated thermogenesis, is also involved in several cellular mechanisms like glucose and fatty acid metabolism, mitochondrial biogenesis and oxidative metabolism, with consequent protective effects against obesity and related disorders (Uldry et al., 2006). The gene discussed is UCP1; the disease is obesity due to melanocortin 4 receptor deficiency.