PDGFRB and digestive system neoplasm: Sorafenib is an inhibitor of VEGFR-1,-2,-3 and PDGFR-β, approved for the treatment of metastatic renal cell carcinoma and unresectable hepatocellular carcinoma (Wilhelm et al., 2006; Escudier et al., 2007), whereas sunitinib blocks VEGFR-2 and PDGFR phosphorylation and is used for gastrointestinal tumor and metastatic renal cell carcinoma (Sun et al., 2003; Motzer et al., 2007).