Gliomas with NTRK fusions have been previously reported to possess co-occurring genetic alterations such as IDH (13, 14, 31), H3.3 K27M (11), H3F3A (40), EGFR amplification (13), EGFRvIII (13), PTEN (13), CDKN2A/2B deletion (11, 37), CDKN2C deletion (37), TP53 mutations/inactivation (13), and ATRX (41), among others (13). The gene discussed is IDH1; the disease is central nervous system cancer.