FLT1 and neoplasm: Bevacizumab is a humanized monoclonal antibody that binds to vascular endothelial growth factor A (VEGF-A) and thus prevents interaction with its receptors, VEGFR-1 (Flt-1) and VEGFR-2 (Flk-1/KDR), leading to the regression of existing tumor blood vessels, normalization of the remaining blood vessels, and consequently tumor inhibition [17].