MAPK3 and neoplasm: Increasing evidence has shown that fucoidans are capable of exhibiting direct and indirect inhibitory effects on tumor cells by regulating several important signaling pathways, such as extracellular signal-regulated kinase 1/2 (ERK1/2) [56,84,88], phosphoinositide 3-kinase-Akt (PI3K/Akt) [84,88], p38 mitogen-activated protein kinase (p38 MAPK) [84], and mammalian target of rapamycin (mTOR) pathways [87,88].