ANGPT2 and hepatocellular carcinoma: In addition to VEGF, other proangiogenic factors including platelet-derived growth factor (PDGF), hepatoctye growth factor (HGF), basic fibroblast growth factor (bFGF), and angiopoietin-2 (Ang2) are also elevated in the HCC plasma and make a substantial contribution to HCC angiogenesis (Semela and Dufour, 2004; Zhu et al., 2011).