XBP1 and cancer: The activated IRE1α catalyzes the splicing of X‐Box binding protein 1 (XBP1) mRNA to form XBP1s, which can regulate the expression of related genes to restore homeostasis and survival of cancer cells.[10] Toyocamycin (Toy), a purine nucleoside analog, has been proven to be an ERS inhibitor to promote tumor cell apoptosis by blocking the IRE1α‐XBP1 pathway.[11] However, the clinical application of free Toy faces great challenges due to its rapid metabolization and low bioavailability.[12]