<p>The interleukin-2 receptor is a heterotrimer composed of one alpha chain, one beta chain, and one gamma chain, all of which are in contact with the ligand when the receptor is occupied [<cite idref="PUB00034966"/>]. IL-2 itself has been shown to regulate IL-2R alpha expression in vitro [<cite idref="PUB00034967"/>].</p> Interleukin-2 receptor alpha chain