FLT4 and colonic neoplasm: Among them are MAZ-51, 3-(4-Dimethylamino-naphthalen-1-ylmethylene)-1, 3-dihydroindol-2-one, an indolinone-based synthetic molecule that inhibits the phosphorylation of the tyrosine kinase receptor VEGFR-3 (27), and SAR131675 ((R)-2-amino-1-ethyl-7-(3-hydroxy-4-methoxy-3-methylbut-1-yn-1-yl)-N-methyl-4-oxo-1,4-dihydro-1,8-naphthyridine-3-carboxamide), a potent and selective VEGFR3 inhibitor with an IC50 of about 20 nM ten times lower than for the other VEGFR, that significantly reduced tumor size and metastases in mouse models of breast (28) and colon cancer (29).