Type 2 inflammation, primarily driven by Th2 cells, group 2 innate lymphoid cells (ILC2), eosinophils, and type 2 cytokines, such as IL-4, IL-5, and IL-1322,23, underlies diseases such as asthma, allergic rhinitis, and atopic dermatitis (AD)24. The gene discussed is IL4; the disease is Alzheimer disease.