NF-κB and the Immunoglobulin κ Gene Enhancer

Enhancers regulate lineage choice and the developmental timing of antigen receptor gene rearrangements. The transcription factor NF-κB has been implicated as a key component of the recombination and transcription activation potential of the immunoglobulin κ chain gene intronic enhancer. Here, I discuss the implications of the new observation that an NF-κB binding site–mutated enhancer in the correct biological context does not appear to affect κgene expression.