The expression of targets of the polycomb repressive complex 2 (PRC2, [41]) strongly decays in LGG and especially in IDH-wt GBM compared with the NL gliomas, which reflects the loss of healthy brain function associated with the progressive de-repression of developmental functions and de-differentiation of neuronal cellular programs in gliomas [28]. The gene discussed is IDH1; the disease is glioma.