In another study, ursolic acid induced autophagy and apoptosis in glioblastoma U87MG cells by three different mechanisms, including phosphorylated extracellular signal-regulated kinase (PERK)/eukaryotic initiation factor 2α (eIF2α)/C/EBP homologous protein (CHOP), calmodulin-dependent kinase protein kinase (CaMMK)/AMPK/mTOR, and inositol-requiring enzyme 1α (IRE1α)/JNK signaling [121]. Here, DDIT3 is linked to glioblastoma.