ERN1 and glioma: As shown by numerous studies, three ER stress sensors, including the protein kinase ribonucleic acid-activated-like ER kinase (PERK), inositol requiring enzyme 1 (IRE1), and activating transcription factor 6 (ATF6), play a significant role in the regulation of glioma proliferation, invasion, epithelial-to-mesenchymal transition (EMT), and chemoresistance (11, 12).