UCP2 and obesity due to melanocortin 4 receptor deficiency: For example, it is noteworthy that polymorphisms in SLC25A8 (encoding UCP2) and SLC25A9 (UCP3) are associated with obesity and type 2 diabetes [182,183]; mutations in SLC25A8 and other genes may lead to hyperinsulinism [184]; and a single nucleotide variation in SLC25A40 (a carrier of unknown function) is linked to hypertriglyceridemia [185].