Sunitinib is a small molecule inhibitor of multiple receptor tyrosine kinases (RTKs), including VEGF receptors (VEGFR-1, VEGFR-2, and VEGFR-3), platelet-derived growth factor receptors (PDGFR-α and PDGFR-β), fms-related tyrosine kinase 3 (FLT3), stem cell growth factor receptor KIT, and RET [7, 8], and is currently considered as a standard first-line treatment for metastatic clear cell RCC (ccRCC) [9, 10]. This evidence concerns the gene FLT3 and nonpapillary renal cell carcinoma.