An elevation of TCRγδ T cells has been observed in some combined immunodeficiencies such as recombination activating gene 1,2 deficiency (21, 22), CD3γ, and CD3δ (23, 24), as a consequence of CMV infection or delayed-onset combined immune deficiency with granuloma and/or autoimmunity (25–27). The gene discussed is CD3D; the disease is cytomegalovirus infection.