GATA3 and Increased total eosinophil count: On the other hand, the recently identified type 2 innate lymphoid cells (ILC2s) also become activated by these cytokines.9, 10, 11 Analogous with TH2 cells, ILC2s require the transcription factor Gata-3 and are a potent source of the type 2 cytokines IL-5 and IL-13, which are able to induce lung eosinophilia and mucus hypersecretion.11, 12, 13, 14, 15 Studies in recombination-activating gene (Rag)−/− mice have shown that these ILC2s are crucial players in allergic airway responses.16