HIF1A and ovarian cancer: Immunohistochemistry revealed that 61.3% (76/124), 41.9% (52/124) and 48.4% (60/124) of ovarian cancer tissues stained positively for SEMA4D, VEGF and HIF-1α, which were significantly higher than the positive staining in normal ovarian epithelial tissues (61.3% vs. 10%, 41.9% vs. 10%, and 48.4% vs. 5%, p < 0.001, respectively; Table 1).