PDGFRB and renal cell carcinoma: Sunitinib is an oral multitargeted tyrosine kinase inhibitor of VEGF receptors (VEGFRs 1–3) and PDGF receptors (PDGFRs α and β), as well as other receptor types, and is approved multinationally for the treatment of advanced renal cell carcinoma (RCC) and imatinib-resistant or -intolerant gastrointestinal stromal tumours (GISTs) (Abrams et al, 2003; Mendel et al, 2003; Murray et al, 2003; O'Farrell et al, 2003; Kim et al, 2006).