FLT4 and neoplasm: The process of tumor lymphangiogenesis includes three key steps: proliferation, migration, and tubule network formation of lymphatic endothelial cells (LECs).37 The survival, proliferation, and migration of LECs depend on the VEGF-C/VEGFR-3 axis, which is known to induce phosphorylation in downstream molecules such as Erk and Akt.27 We first investigated the phosphorylation of VEGFR-3, Akt, and Erk of human LECs (hLECs) after treatment with anlotinib and SAR131675 by Western Blots.