CD163 and central nervous system cancer: To confirm the association between existence of M2 macrophages and clinicopathological variables, we've firstly detected the existence of M2 macrophages in glioma tissues and paired normal controls in our setting, using IHC method with the cell surface marker CD68 (pan-macrophage marker) in combination with CD163 (M2 macrophage marker), which have been widely adopted and employed in the evaluation of M2 macrophage prevalence in cancers.