ERN1 and Hyperglycemia: With regard to IRE1α the functional analysis of this molecule in adult KO mice has been lagging because the KO mice suffer embryonic lethality; however, we could show here using the conditional KO method that IRE1α-deficient mice exhibit mild hypoinsulinemia, hyperglycemia, and a low-weight trend, and that IRE1α disruption causes histological abnormality of the pancreatic acinar and salivary serous tissues and decrease of serum level of immunoglobulin produced in the plasma cells.