An antibody directed against the human alpha5beta1 integrin (a5b1) with potential antiangiogenic and antineoplastic activities. Anti-a5b1 antibody MINT1526A selectively binds to a5b1, thereby 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 a5b1-expressing tumor cells. a5b1, a cell adhesion and signaling receptor, is often overexpressed on the surface of tumor vessel endothelial cells and plays a crucial role in both endothelial cell adhesion and migration.