IDH1 and oligodendroglioma: We observed major driver gene mutations known in oligodendroglioma, including CIC (6/9), FUBP1 (3/9), TP53 (3/9), Notch1 (3/9), KRAS (2/9), PIK3R1 (1/9), BOCR (1/9), SMARCB1 (1/9), and ATRX (1/9), accompanying with IDH‐mutant and 1p/19q co‐deletion (Figure 1B).