IGF2 and cancer: There are many types of autocrine growth factors, with the major ones in cancer being vascular endothelial growth factor (VEGF), epidermal growth factor (EGF), insulin-like growth factor-2 (IGF-2), epidermal growth factor receptor (EGFR) and 5-hydroxytryptamine (5-HT; serotonin), to name a few [117–120].