ERN1 and diabetes mellitus: It has been reported that modulating the unfolded protein response (UPR) in β cells of nonobese diabetic (NOD) mice by deleting the UPR sensor IRE1α prior to insulitis induced transient dedifferentiation of β cells, resulting in substantially reduced islet immune cell infiltration and β cell apoptosis, and IRE1α-deficient mice exhibited significantly fewer cytotoxic CD8+ T cells in their pancreata, and adoptive transfer of their total T cells did not induce diabetes [54].