In this study, we demonstrated that sunitinib inhibited VEGFR-3 and VEGFR-2 signaling under VEGF-C or VEGF-D stimulation, and that it interfered with the cellular functions of LECs induced by VEGF-C, thereby inhibiting lymphangiogenesis and lymph node metastasis in a breast cancer model. The gene discussed is FLT4; the disease is breast carcinoma.