Barmettler et al. also observed a correlation between low CD4+ T-helper cells and low specific antibody responses in their mixed cohort of individuals with secondary and severe primary PADs, including complicated CVID/SpAD, activated P13K-syndrome, TACI deficiency, NFKB1 deficiency, HGG, and IgG subclass deficiency. The gene discussed is CD4; the disease is common variable immunodeficiency.