CCR6 and infection: Although CCR6− ILC3s produced less IL-22 than CCR6+ ILC3s, they remain to be an important source of IL-22.21 Unlike most interleukin receptors, the IL-22 receptor is mainly expressed on non-hematopoietic cells, especially epithelial cells.185 IL-22 maintained barrier integrity and the containment of intestinal bacteria at steady state and was shown to be protective in various infection models, including C. rodentium, C. difficile, Rotavirus, and Salmonella Typhimurium (S. Typhimurium) infection.16,113,178,186,187C.