NFKB1 and Immunodeficiency: As recent cases of NF-κB1 haploinsufficiency have been shown associated with EBV infection (8, 13) and EBV-lymphoproliferative disease with T-cell dysfunction (7), we compare NF-κB1 haploinsufficiency with other EBV-associated PIDs, discuss combined immunodeficiencies related to NF-κB by shared signaling pathways but without sign of EBV-associated disease, and outline the consequences of NF-κB1 dysfunction for T-cell integrity resulting in a proposed impairment of EBV clearance.