ATRX and glioblastoma: ATRX (particularly without IDH or TP53 mutations) or GBM with mutations in the SWItch/Sucrose Non-Fermentable (SWI/SNF)-related, matrix associated, actin-dependent regulator of chromatin subfamily A-like 1 (SMARCAL1) include an ALT-positive TERTpWT-IDHWTGBM subgroup known as IDHWT-ALT 9.