Gehring MP et al. showed that P2X7 activation increased effectiveness of radiotherapy using GL261 and M059J cell lines which were sensitive to ATP-P2X7R-induced cell cytotoxicity [85], whereas we performed our studies using LN-229, U-251, and U-138 glioma cells, in which P2X7 did not induce cell death. This evidence concerns the gene P2RX7 and glioma.