VEGFA and hepatocellular carcinoma: In an in vivo study using subclones of drug-resistant human HCC cells established by long-term treatment with vascular endothelial growth factor (VEGF) receptor inhibitors and serial transplantation into immunocompromised mice, thymosin beta 4 (Tβ4), a G-actin monomer binding protein, is enriched in resistant HCC cells, and DNA demethylation and histone H3 activation at its promoter region result in an aberrant expression of Tβ4, promoting the growth of sorafenib-resistant tumors [40].