RETN and obesity due to melanocortin 4 receptor deficiency: Not only is the adipokine resistin associated with obesity, inflammation, and various cancers 32,33,34, but high serum resistin levels have been implicated in the pathogenesis of cachexia in lung cancer 35, while resistin overexpression or upregulation is a feature of several human cancers, including oral cancer, renal cell carcinoma, chondrosarcoma and colon cancer 36,37,38,39.