Sunitinib is an oral small molecular weight inhibitor of VEGFR 1, 2, and 3, PDGFR α and β, KIT, Fms-like tyrosine kinase-3 (FLT3), colony stimulating factor receptor (CSF-1R), and the glial cell-line derived neurotrophic factor receptor (RET) approved for the treatment of advanced RCC in patients in the first line or second line setting [12]. The gene discussed is FLT3; the disease is renal cell carcinoma.