Schema of antiplatelet GPIIIa49-66 scFv Ab (A11) properties for the inhibition of tumor metastasis. (A) Summary figure. Events occurring following tumor intravasation, tumor-platelet-endothelial cell binding and platelet-tumor thrombus formation, tumor-platelet embolization, angiogenesis, and extravasation. T indicates tumor cells; and AP, activated platelets. (B) Platelets promoting metastases in an experimental pulmonary metastasis B16 tumor model. (Top row) Lung specimens with metastastic colonies. Plt indicates platelet. (Bottom row) Numeric results of surface pulmonary nodules (n = 8, **P < .01). (C) Hypothesized mechanisms of A11 on the inhibition of tumor metastasis by lysing activated platelets within the tumor microenvironment.