Among genes with positive associations of variants with obesity or obesity-related phenotypes, there are some deeply involved in the regulation of mitochondrial activity and biogenesis in adipose tissues, like ADRB3 (adrenergic, β3 receptor), INS (insulin), PLIN (perilipin), PPARγ (peroxisome proliferative activated receptor, gamma), or UCP1-UCP13 (uncoupling proteins 1–3) [104]. The gene discussed is UCP1; the disease is obesity due to melanocortin 4 receptor deficiency.