Similarly, for the six cases with TERT promoter mutant tumors, we observed the presence of the TERT promoter mutation solely in the cerebrospinal fluid (CSF) of a case with DMG, while it was not detected in the CSF of the three H3-wildtype-astrocytomas or two ependymomas (Fig. 3c–e). The gene discussed is TERT; the disease is ependymoma.