S1PR1 and colorectal carcinoma: Lipid-associated changes can stimulate cell signalling crucial for the induction of angiogenesis; for example, LPAs induce the secretion of angiogenic factors in CRC cells [141], S1PR1 is essential for vascular barrier functions [7], and PGE2 has been shown to induce vascular endothelial growth factor (VEGF) [79,150].