OPN is the major phosphoprotein secreted by malignant cells in patients with advanced metastatic cancer, is frequently overexpressed in human tumors, and has been implicated as a key mediator of tumor cell metastasis.
Further study demonstrated that VEGF/OPN-BsAb could effectively suppress primary tumor growth and metastasis to lungs, suggesting that it might be a promising therapeutic agent for treatment of metastatic cancer.