While our median follow-up in IDH-mut astrocytomas was longer than the current follow-up of the CATNON trial (6.6/4.7 years), WHO grade II IDH-mut astrocytomas in our cohort also had a significantly longer median OS than WHO grade III tumors (5.8 years difference). The gene discussed is IDH1; the disease is astrocytoma (excluding glioblastoma).