Circulating ghrelin levels are reported to increase in underweight patients with malignancy-associated cachexia (Shimizu et al., 2003; Garcia et al., 2005) and tumor-bearing animals (Terawaki et al., 2014), suggesting a failure of the adaptive feeding response by endogenous ghrelin (Schwartz et al., 1995; Schwartz and Seeley, 1997; Flier, 1998). This evidence concerns the gene GHRL and neoplasm.