PDGFRB and hepatocellular carcinoma: Cotreatment of the HCC cell lines with 200-nM AMC303 and 1-μM (SNU423) or 5-μM (SNU449) sorafenib as well as 5-μM (SNU423) or 10-μM (SNU449) regorafenib led to a significant reduction in cell viability (Fig. 5A), indicating that CD44v6 inhibition sensitizes HCC cells to VEGFR, PDGFR and RAF kinase inhibitors.