LEP and cancer: Central regulators of energy metabolism, such as hypothalamic orexigenic neuropeptide Y (NPY) and anorexigenic cocaine and amphetamine regulated transcript (CART) peptide and peripheral regulators, such as leptin (LEP), ghrelin (GHRL) adiponectin (ADIPOQ), and cholecystokinin (CCK), are known to be dysregulated in various cancers and to contribute to malignancy (reviewed in [3]).