XBP1 and glioblastoma: Our previous study showed that TAK-243 enhanced GBM cell apoptosis by inducing endoplasmic reticulum (ER) stress and activating PERK/eIF2/ATF4 and IRE1α/XBP1 signaling pathways, two major unfolded protein response (UPR) activation pathways (Zhang et al., 2022b).