IGF1 and colorectal carcinoma: Numerous NE peptides (e.g., cholecystokinin, bombesin, SST), and growth factors (e.g., PDGF, EGF, IGF-1, FGF-2, VEGF, TGF-β), which are integral components of well-known signaling pathways, play an important role in the pathogenesis of CRC [6,11,12,13,14].