HSPG2 and cancer: It should be noted that various signaling molecules downstream of MAS-R are activated and involved in cancer pathogenesis, such as phosphoinositide 3-kinases (PI3k)/protein kinase B (Akt), NADPH oxidase (NOX), AMP-activated protein kinase (AMPK)/forkhead box protein O1 (FoxO1), phospholipase C (PLC), inositol trisphosphate (IP3), p38 mitogen-activated protein kinase (p38 MAPK), and the mammalian target of rapamycin (mTOR), all of which are potential targets for future studies (for review, [39]).