FLT1 and colorectal carcinoma: VEGFR-1 [also named Fms-like tyrosine kinase-1 (FLT1)] and VEGFR-3 [also named Fms-related tyrosine kinase 4 (FLT4)] have been shown to be involved in tumor progression and metastasis in CRC, and VEGFR-2 (also named fetal liver kinase FLK1/KDR) has been implicated in endothelial cell survival, proliferation and migration (21, 22).