A monoclonal antibody directed against the human alpha5beta1 integrin with potential antiangiogenic and antineoplastic activities. Anti-alpha5beta1 integrin monoclonal antibody PF-04605412 selectively binds to alpha5beta1 integrin, preventing the binding of integrin ligands. This may result in the inhibition of endothelial cell-cell interactions, endothelial cell-matrix interactions, and integrin-mediated tumor angiogenesis and metastasis in alpha5beta1-expressing tumor cells. Alpha5beta1 integrin, a cell adhesion and signaling receptor, is often overexpressed on the surface of tumor vessel endothelial cells and plays a crucial role in endothelial cell adhesion and migration.