Innate Lymphoid Cells (ILCs) are a recently identified family of innate immune cells. Their accurate analysis allows the understanding of how they contribute to host defense, tissue morphogenesis, homeostasis and repair, and pathological conditions such as immunodeficiencies, autoinflammatory diseases, and autoimmunity. The main interests of this research area are Natural Killer (NK) cells, cytotoxic innate lymphoid cells circulating in the blood and detectable in tissues and characterized by the ability to efficiently kill tumor or virus-transformed cells