NFKB1 and combined immunodeficiency: In the USIDENT study, AD was most commonly reported in patients with a deficiency of the nuclear factor κB (NFkB) essential modulator (62.5%), the Wiskott–Aldrich syndrome (WAS: 41.5%), combined immunodeficiency (CID: 33.3%), selective IgM deficiency (33.3%), and autosomal-dominant hyper-IgE syndrome (AD-HIES; 25%) [8,16].