CELLS OF THE IMMUNE CELLS Innate Lymphoid Cells (ILC) Group Cells Cytokines and mediators Activity  1st group Thymic NK cells IFN-γ T-cell lymphopoiesis NK cells (often considered as a separate lineage) IFN-γ, perforin, and granzymes Natural cytotoxicity ILC1 IFN-γ Defense from intracellular pathogens, tumors  2nd group ILC2 IL-5, IL-9, IL-13, TSLP, and amphiregulin Allergic inflammation, defense from helminths, wound repair, Th2 regulation  3rd group LTi cells (often considered as a separate lineage) TNF-β, IL-17, and IL-22 Development of lymphoid cells including Peyer's patches, intestinal homeostasis, defense from extracellular pathogens NCR+ILC3 (ILÑ22) IL-22 Maintenance of epithelium integrity, Th22 regulation NCR-ILC3 (ILÑ17) IFN-γ and IL-17 Defense from extracellular pathogens, Th17 regulation Innate Lymphoid Cells (ILCs) is a collective term for neither T cells nor B cells. ILCs are involved in the innate immunity, inflammation, lymphoid tissue development, and immunoregulation. Among described ILCs, one ILCs subgroup, NK cells, have been identified many years ago. ©V.V.Klimov