VEGFA and metastatic colorectal cancer: Bevacizumab (Avastin, Genentech Inc., San Francisco, CA) is a 149 kD humanized monoclonal antibody directed against all isoforms of vascular endothelial growth factor A (VEGF-A), approved by the US Food and Drug Administration (FDA) in February 2004, for intravenous use in metastatic colorectal cancer.