XBP1 and cancer: DSF/Cu targets the p97 segregase adaptor NPL4 [23], inhibits NF-κB [20, 24], and activates endoplasmic reticulum stress by upregulating the inositol requiring-enzyme 1 alpha (IRE1α)–X-box-binding protein 1 (XBP1) axis, which leads to autophagic apoptosis [25], inducing ICD in both differentiated and IR-resistant cancer stem cell (CSC) populations [26, 27].