Background：CD132 is a 64-70 kD type I transmembrane glycoprotein of the Ig superfamily, and is also known as common gamma chain （gammac） or IL-2 receptor gamma subunit. It is expressed broadly on T- and B-lymphocytes, NK cells, monocytes, and granulocytes. CD132 is an essential component of cytokine receptors for IL-2, IL-4, IL-7, IL-9, IL-15, and IL-21. Ligand binding induces tyrosine phosphorylation and initiates signaling through a JAK/STAT pathway. CD132 mutation results in X-linked severe combined immune deficiency （XSCID）.
