IDH2 and central nervous system cancer: Third, limited by the size of the overall population, the classification performance to differentiate either IDH mutant 1p/19q codeleted (14/69) and non-codeleted (18/69) tumors from other subtypes was not reliable (differentiation of IDH mutant 1p/19q non-codeleted, F1-score 0.49; differentiation of IDH mutant 1p/19q non-codeleted, F1- score 0.48; other detailed data not shown); hence, we combined these two groups as IDH mutant gliomas.