Background
This gene encodes an immunoregulatory cytokine produced primarily by activated Th2 cells.
This cytokine is involved in several stages of B-cell maturation and differentiation. It upregulates CD23 and MHC class II expression, and promotes IgE isotype switching of B cells.
This cytokine down-regulates macrophage activity, thereby inhibits the production of proinflammatory cytokines and chemokines. This cytokine is found to be critical to the
pathogenesis of allergen-induced asthma but operates through mechanisms independent of
IgE and eosinophils. This gene, IL3, IL5, IL4, and CSF2 form a cytokine gene cluster on
chromosome 5q, with this gene particularly close to IL4
