HCRTR1 and colonic neoplasm: The OX1R activation in colon cancer cells by exogenous orexins (OxA or OxB) induced the mitochondrial caspase-dependent apoptosis (28) The OxA/OX1R system was responsible for the anti-tumoral impact in preclinical models in which colon cancer cells were xenografted and also in preclinical models where pancreatic or liver cancer cells were xenografted (15, 19, 29).