IDH1 and astrocytoma (excluding glioblastoma): Comparison of the methylation landscapes by means of the pairwise correlation map, river flow plot, and number distributions reveals a clear shift with age from prenatal and newborns brain with similarity to M1 (IDH-wt), of babies and young children resembling partly astrocytoma-like IDH-A of the M4 group (highly methylated IDH-A core group), of adults with similarity to GCIMP-low IDH-A LGG of the M2–M3 groups showing inflammatory characteristics of the tumor microenvironment and of elderly people with IDH-O LGG possessing relatively high proliferative characteristics (M5) (Figure 8a–d).