NTRK1 and glioblastoma: Moreover, the well-established presence of GBM stem cells (GSCs) within primary tumors, along with the substantial transcriptional heterogeneity and plasticity found within GBM, raises a number of questions regarding whether histone PTMs and chromatin architecture play a role in regulating transcription and degree of differentiation, as exemplified by the role of specific histone demethylases in treatment escape in GSCs exposed to prolonged receptor tyrosine kinase inhibition (6, 31–36).