TERT and glioblastoma: In contrast, low levels of ZDHHC18 and ZDHHC23 mRNA are associated with other positive prognostic markers including the loss of TERT, mutations of ATRX and IDH1, 1p/19q codeletion, and methylation of MGMT. Notably, the stem cell state of GBM might be reflected by the expression levels of ZDHHC23 and ZDHHC18, as these DHHC proteins can be expressed in regular neural stem cells.