In TM-deficient oligodendrogliomas, we found an upregulation of the NOTCH1 pathway, both in the BT088 cell line and human samples, which is in line with the principal regulation of TM networks by NOTCH1. However, our analyzes also show fundamental biological differences between 1p/19q-codel oligodendrogliomas and 1p/19q-intact other glioma types: in contrast to astrocytomas and glioblastomas, the NOTCH1 pathway activation in oligodendroglioma seems not to be strongly related to PVN position and cells in the PVN were not slow cycling. Here, NOTCH1 is linked to glioblastoma.