GHRL and colorectal cancer: Ghrelin, its native receptor (GHSR1a) and the truncated receptor (GHSR1b), have been described in renal cell carcinomas and neuroendocrine tumors, including pituitary, pancreatic, thyroid, lung, breast, gonadal, prostate, ovarian, oral, gastric and colorectal cancer, using inmunohistochemistry or RT-PCR [42,57,58].