In particular, the ionotropic ATP receptor P2RX7 is known to be associated with GBM tumor formation, and we and others have shown that P2RX7 is expressed and functional in both GL261-AC and GL261-NS cells (Tamajusuku et al. 2010; Strong and Daniels 2017; Strong et al. 2018). This evidence concerns the gene P2RX7 and glioblastoma.