BCL2 and glioblastoma: For instance, nuclear import receptor karyopherin β1 (KPNB1) apoptotic functions impede UPR activity in GBM U87 and U251 cells, whereas KPNB1 depletion initiates terminal UPR signaling to inhibit anti-apoptotic regulators and promote pro-apoptotic pathways via Bcl-2 protein family regulation.