For the first time, our study characterizes GBM inosinome in a comprehensive and transcriptome-wide manner, disclosing a strong and peculiar perturbation of inosinome landscape in GBM compared to normal brain never described before and involving all the three ADAR proteins as tested in two independent de novo GBM cohorts of patients (TCGA and CGGA). Here, ADAR is linked to glioblastoma.