As outlined, future studies are required to validate findings from preclinical models and to adequately test these hypotheses in humans, especially regarding a better understanding of cytokines, ghrelin, sclerostin, PTH, cholecystokinin, GLP-1, and PYY physiology, their roles in obesity and BS, and their therapeutic potentials. This evidence concerns the gene PYY and obesity due to melanocortin 4 receptor deficiency.