IL-5 promotes eosinophilia, and IL-4 and IL-13 enhance the production of eosinophil chemoattractants (CCL11/eotaxin-1, CCL24/eotaxin-2, and CCL26/eotaxin-3) and activate B cells, macrophages, fibroblasts, epithelial cells, and goblet cells. The gene discussed is IL4; the disease is Increased total eosinophil count.