There is also an intermediate G-CIMP subgroup in recurrent cases, representing those which are slowly evolving from low to high grade, and trending from G-CIMP-high to G-CIMP-low ("epigenetic plasticity”), which is associated with malignant progression [55], similar in concept to rising CNA levels with increasing grades of IDH-mutant astrocytoma [175]. This evidence concerns the gene IDH1 and astrocytoma (excluding glioblastoma).