ILC2 are found in human respiratory and gastrointestinal tissue as well as in skin.Studies from mouse models of asthma and atopic dermatitis suggest a role for ILC2 in promoting allergic inflammation.The epithelial cytokines IL-25, IL-33, and TSLP, as well as the lipid mediator leukotriene D4, have been shown topotently activate ILC2 under specific conditions and supporting the notion that many separate pathways in allergic diseasemay result in stimulation of ILC2. The gene discussed is TSLP; the disease is asthma.