Bevacizumab is a humanized IgG1 monoclonal antibody specific for VEGF-A, a cytokine critical for angiogenesis (the growth of new blood vessels) in both normal tissues and tumors. As the first clinically available angiogenesis inhibitor in the United States, Bevacizumab is used for treatment of certain metastatic cancers, lung cancers, renal cancers, ovarian cancers, breast cancers, and glioblastoma multiforme.