Source:http://linkedlifedata.com/resource/umls/id/C1744318
NCI: CRE Recombinase catalyses site-specific recombination between two 34 base pair loxp sites and maintains the phage genome as a monomeric unit-copy plasmid in the lysogenic state. CRE is a homotetramer when bound to DNA and belongs to the phage integrase family. (from SWISS-PROT P06956 and NCI)