T-cell surface glycoprotein CD3 gamma chain is a protein that in humans is encoded by the CD3G gene.
T cell antigen receptor (TCR) is associated on the T cell surface with a complex of protein called CD3. CD3G (gamma chain) is one of the four peptides (gamma, delta, epsilon and zeta) that form CD3. Defects in CD3G are associated with T cell immunodeficiency.[5]