VEGFA and cancer: Clinical trials of bortezomib in combination with bevacizumab (Bev), our previous study has revealed that secreted AGR2 directly binds to VEGF and enhances VEGFR2 signaling, leading to the interruption of antitumor activity of bevacizumab, a humanized monoclonal antibody that inhibits VEGF activity and has been approved for patients with cancers [10].