Expression of OX40L in human glioblastoma. a. OX40L mRNA expression in grade IV glioma (glioblastoma) (n = 110) and grade III glioma (n = 34, *P < 0.05). b. Representative immunohistochemical images of glioblastoma specimens stained with Tag34, anti-human-OX40L antibody (brown). The left panel shows a tumor tissue section with many OX40L-positive cells and the right panel shows a tumor tissue section with limited positive cells. Scale bar, 40 μm.