ERN1 and diffuse large B-cell lymphoma: Numerous instances exist, such as the inhibition of phosphoglucomutase 3 (PGM3) activating UPR to counteract gemcitabine resistance in pancreatic cancer [119], and the activation of the IRE1–XBP1 pathway of UPR overcoming ibrutinib resistance in diffuse large B-cell lymphoma [120] (Table 1).