The somatic recombination of lymphocyte antigen receptor loci is integral to 
lymphocyte differentiation and adaptive immunity. Here we review the relation of 
this highly choreographed process with the zinc finger protein CTCF and with 
cohesin, a protein complex best known for its essential functions in 
post-replicative DNA repair and chromosome segregation during the cell cycle. At 
lymphocyte antigen receptor loci, CTCF and cohesin shape long-range interactions 
and contribute to V(D)J recombination by facilitating lineage- and 
developmental-stage-specific transcription and accessibility.