A critical role for IL-22 signaling via IL-22Ra1-STAT3 has been established in modulating mucosal immunity, microbiota colonization, inflammation, and tissue repair.1–6 Currently, recombinant human IL-22 IgG2-Fc (IL-22.Fc) fusion protein is in FDA-approved phase IIa clinical trials for graft vs host disease (trial ID NCT0246651) and alcoholic hepatitis (NCT 02655510). The gene discussed is IL22; the disease is alcoholic hepatitis.