KDR and metastatic colorectal cancer: Bevacizumab is a recombinant humanized anti-VEGF immunoglobulin G1 (IgG1) approved as an antiangiogenic agent for the treatment of metastatic colorectal cancer in combination with chemotherapy.6 By binding to two receptor kinases [VEGFR-1 (Flt-1) and VEGFR-2 (KDR, Flk-1)], bevacizumab is able to downregulate the mitogenic, angiogenic and permeability-enhancing effects of VEGF A. Avastin® (bevacizumab) is clear to slightly opalescent, colorless to pale brown, sterile solution with pH 6.2.