We analyzed the endogenous ADAR2 level (mRNA and protein) in several human GBM cell lines (A172, T98G, U118MG, U87MG, LN18, and U138-MG) that show diverse abilities to give rise to a growing tumor mass if implanted in a mouse model (www.atcc.org, accessed on 1 January 2022) (Figure 2a,b). This evidence concerns the gene ADARB1 and glioblastoma.