FLT1 and melanoma: As a class III/V multikinase inhibitor, Sunitinib was reported to suppress various kinds of tumors, such as human metastatic renal cell carcinoma, lung carcinoma, glioblastoma, melanoma [12–15] by inhibiting the activation of VEGFR-1, 2 and 3, PDGFR-α, β, Kit, Flt3 and RET.