Table 1.

Summary of layers of regulations influencing NF-κB-driven gene transcription.

Quantity	Influential factors
ABUNDANCE
κB binding sites	Number of sites Consensus vs. non-consensus sites Duration and frequency of interactions with DNA Cumulative occupancy of binding sites Avidity vs. decoy site effects of clusters Cooperative vs. independent binding at promoters
Nucleus-localized NF-κB dimers	Homodimerization and heterodimerization Transcription activators vs. repressors Stimulus- and time-dependent changes Competition for subunits in dimerization
AFFINITY
NF-κB dimers for κB sequences	Diversity of bound sequences Dimer-specificity of binding sites Dimer switching and temporal patterns Sequence-specific conformational changes Post-translational modifications of NF-κB subunits
AVAILABILITY
Chromatin state	Histone acetylation and poised chromatin state Cell-type specificity and stimulus-dependence Nearest gene: accessed in 2- vs. 3-dimensions
Competition between NF-κB dimers	Relative abundances Activating vs. repressive dimers Pre- and post-stimulus changes
Co-regulators of transcription	Pre-existing vs. recruited co-regulators HDACs and HATs recruitment Cell-type specificity and stimulus-dependence

Factors that influence NF-κB-driven gene transcription, its “layers of regulation,” organized by the quantity, abundance, affinity, or availability, with which they were associated in the organization of this review.