The primary function of one such adipocyte-secreted hormone and biomarker of adiposity,74,75 leptin, is hypothalamic-mediated regulation of appetite, which modulates feeding behaviour and energy expenditure.76,77 Circulating levels of leptin are elevated in obese individuals and are associated with an increased risk of the development and progression of cancer, such as endometrial, breast, colon, and kidney cancers, among others.78–80. This evidence concerns the gene LEP and cancer.