GHRL and colorectal cancer: The components of the ghrelin system are expressed in tissues and cell lines from GI tract cancers, including human neuroendocrine tumours [4,52,53,54], GI stromal tumours (GIST) [55,56], oesophageal, gastric, pancreatic and liver cancers [57,58], and colorectal cancer (CRC) [58,59,60,61,62].