To investigate the resistance of tumor‐derived endothelial cells (TDECs) to anti‐angiogenic therapyTo identify new anti‐angiogenic drugs that can target glioblastoma, particularly those effective against VEGF‐independent angiogenesisTo evaluate the potential of sertraline as an anti‐angiogenic agent in combination with the VEGF receptor inhibitor axitinib. Here, VEGFA is linked to neoplasm.