KDR and renal cell carcinoma: Sunitinib is a tyrosine kinase inhibitor (TKI) which is usually used in adjuvant targeted therapy.[15] It can inhibit several receptors which have an effect in tumorigenesis and tumor progress of RCC, including vascular endothelial growth factor receptors (VEGFRs, like VEGFR-1, VEGFR-2, VEGFR-3) and c-Kit.[16,17] Angiogenesis is mandatory in the progression of RCC since it provides tumor tissues with adequate oxygen and nutrients.