Indirect stimulation of IL-22RA1 through IL-22 gene transduction or IL-22–producing immune cell transfer has shown beneficial impacts in small intestinal epithelial regeneration (Lindemans et al., 2015) and in dextran sodium sulfate (DSS)–induced ulcerative colitis (Sugimoto et al., 2008; Zenewicz et al., 2008). Here, IL22 is linked to ulcerative colitis.