Notably, 2 recent studies reported that the CDKN2A deletion was prognostic for IDH-mutant astrocytoma, which will be incorporated in the new grading criteria.10,11 Our results suggest that CDKN2A/B deletion may also be prognostic for IDH-wildtype GBM and deserves further investigation. The gene discussed is IDH2; the disease is glioblastoma.