This gene encodes one of the subunits of the transcription factor complex nuclear factor-kappa-B (NFkB). The NFkB transcription factor complex is expressed in numerous cell types and functions as a central activator of genes involved in inflammation and immune function. The NFkB complex can consist of different subunits that form both homo- or heterodimers which bind specific kappa-B elements in target genes. This gene encodes the p100 subunit that is processed into the active p52 subunit. This protein can function as both a transcriptional activator and repressor, depending on its dimer partner. Alternate splicing results in both coding and non-coding variants.