ERN2 and colitis: Through a longitudinal follow-up of up to 1 year, IRE1β–/– mice did not spontaneously develop intestinal inflammation, when exposed to DSS, and IRE1β–/– mice pronounced earlier alterations compared to wild-type mice, including marked shortening of the long axis, inflammatory cells infiltration consisting predominantly of mononuclear cells, and ulceration consisting of focal lesions interspersed with areas with intact surface epithelium, which suggested that mutant mice were prone to developed colitis earlier.