An extensive study on astrocytomas that were either R132H-mutated or had non-canonical IDH1/2 mutations showed that non-R132H IDH1/2-mutated tumors had overall increased DNA methylation, decreased gene expression, and better prognosis, suggesting an intriguing possibility of differences in phenotype intensity within IDH1 mutants and/or among IDH1 and IDH2 mutants (24), while others have shown that there is no difference in overall survival when comparing non-canonical and canonical IDH1 mutations found in grade 4 astrocytomas (25). Here, IDH1 is linked to astrocytoma (excluding glioblastoma).