IDH1 and astrocytoma (excluding glioblastoma): Alpha-thalassemia/mental retardation syndrome X-linked (ATRX) mutation and loss of expression, and tumor protein p53 (TP53) mutation are more frequent in astrocytomas and telomerase reverse transcriptase (TERT) promoter mutation confers favorable prognosis in adult LGGs with IDH1/2 mutations, these are also important markers of clinical behavior [10, 11].