LEP and obesity due to melanocortin 4 receptor deficiency: This finding led to the discoveries of the obesity gene (ob) and a number of hormones derived from adipocytes such as leptin, adiponectin, and resistin, and various pro- and anti-inflammatory molecules termed adipokines, which redefined the endocrine and metabolic function of adipose tissue.19 These molecules have been shown to have autocrine/paracrine effects locally as well as an endocrine effect systemically, allowing them to act at the metabolically relevant organs, including the brain, liver, muscle, adipose tissue and pancreas.