Patients with the above-mentioned comorbidities and immunosuppressive therapies have common abnormalities in T cell numbers or function, the decreased total CD4+ T cell count is associated with recurrent infections, the decrease of naive CD4+T cell or natural killer (NK) cell ratio is associated with autoimmunity and decreased NK cell count in CVID patients seemed to have no association with viral infections (4, 5). The gene discussed is CD4; the disease is infection.