Mice lacking IRE1β are sensitive to colitis induced by dextran sodium sulfate challenge (Bertolotti et al., 2001), as are animals lacking XBP1 (Kaser et al., 2008), ATF6, or the ER cochaperone p58IPK/ERDJ6 (Cao et al., 2013). The gene discussed is DNAJC3; the disease is colitis.