These molecules drive type-2 immune responses, promoting the secretion of IL-4, IL-5, IL-9, and IL-13 initially from group 2 innate lymphoid cells (ILC2s),5–7 and subsequently from T helper 2 (Th2) cells.8,9 This promotes eosinophilia, mucus production, smooth muscle contraction, IgE class switching in B cells, and alternatively activated macrophages (AAM). The gene discussed is IL5; the disease is Increased total eosinophil count.