Allelic variations in this gene have been associated with atopy, a condition that can manifest itself as allergic rhinitis, sinusitis, asthma, or eczema.

Two transcript variants encoding different isoforms, a membrane-bound and a soluble form, have been found for this gene.

[6] Interactions of IL-4 with TNFα promote structural changes to vascular endothelial cells, thus playing an important role in tissue inflammation.

Alternatively activated macrophages (AAMΦ) downregulate inflammatory mediators such as IFNγ during immune responses, particularly with regards to helminth infections.

They are required for binding of interleukin-4 to the receptor alpha chain, which is a crucial event for the generation of a Th2-dominated early immune response.