FLT4 and lung carcinoma: To test their effects on the activation of the VEGF-C/VEGFR-3 axis, A549 lung cancer cells with endogenous VEGFR-3 expression or 293T cells with ectopic VEGFR-3 expression (293T/VEGFR-3) were treated with peptides for 24 hours and then assayed to determine VEGF-C-induced VEGFR-3 Tyr1063/1068 phosphorylation.