ATRX mutation and aberrant p53 expression are frequently present in IDH-mutant astrocytomas, which exhibit chromosomal instability and the ALT phenotype, eventually progressing to glioma (Heaphy et al., 2011; Marinoni et al., 2014; Ohba et al., 2020) (Figure 2). This evidence concerns the gene ATRX and astrocytoma (excluding glioblastoma).