The human glioma cell clusters in culture were P2X7R positive. A: Cell cluster of glioma cells (GFAP positive, red) also expressed P2X7R receptor (green). Scale, 100 μm. B: Magnified image of a glioma cell (GFAP positive, red), also expressing P2X7R (green). Image in the right showing the co-localization of GFAP and immunoreactivity for P2X7R. Scale, 50 μm. C: Cell cluster in human glioma culture labeled for microglia (isolectin GS-IB4, red), also showed P2X7R immunoreactivity (green). Scale, 50 μm. D: Magnified image of a microglia (isolectin GS-IB4 positive, red) showing expression of P2X7R (green). Right image shows co-localization of isolectin GS-IB4 and P2X7R immunoreactivity. Scale, 10 μm.