IDH1 and astrocytoma (excluding glioblastoma): Although EGFR status showed statistically significant lower survival within grade 2-3 tumors, MYC amplification, PTEN loss, and CDKN2A loss status were associated with tumor progression.8 Generally, none of the studies found EGFR amplification to be an independent marker of worse OS within grade 4 IDH-mutant astrocytomas, unless it co-occurs with CDKN2A/B loss, MET amplification, and/or G-CIMP-low status.