A humanized IgG1 monoclonal antibody directed against the epidermal growth factor-like domain multiple 7 (EGFL7) with potential antineoplastic activity. Anti-EGFL7 monoclonal antibody MEGF0444A binds to EGFL7, thereby preventing the activities of EGFL7 on endothelial cells and inhibiting the survival and migration of endothelial cells during angiogenesis. EGFL7, a vascular-restricted extracellular matrix protein which is upregulated during angiogenesis and which regulates vascular development, may be overexpressed on the cell surfaces of various solid tumor cell types.