The gene signatures of subpopulations D and E, cortex subpopulation A, cortex development (A1 and A2), and cortex injury (B2) were most highly correlated with LGG samples bearing the IDH mutation and the 1p/19q codeletion; they are also positively associated with oligodendroglioma histology. This evidence concerns the gene IDH2 and oligodendroglioma.