KDR and hepatocellular carcinoma: HCC is characterized by its hypervasculature resulting from higher expression of angiogenesis promoting factors, especially VEGF and VEGF-R, but also other pro-angiogenic factors, such as angiopoietin 2, PDGF, EGF, FGF, TGF-α, and endoglin [55,57,59,60,61].