NFKB1 and immune system disorder: Mutations in genes that affect nuclear factor κB (NF-κB)–dependent signaling are associated with a number of immunodeficiencies.13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26 NF-κB is a ubiquitous transcription factor member of the Rel proto-oncogene family.