The Labrador Retriever, Labrador or just Lab, is a medium-large breed of retriever-gun dog. The second (E) locus determines whether the eumelanin is produced at all. A dog with the recessive e allele will produce only phaeomelanin pigment and will be yellow regardless of its genotype at the B locus. The genes known about previously have had their number increased by the introduction of the K locus, where the dominant 'black' allele KB is now known to reside. There is no global registry of Labradors, nor is there detailed information on numbers of Labradors living in each country. As of 2005, the five countries with the largest numbers of Labrador registrations are the United Kingdom, France, the United States, Sweden and Finland. As of 2005, the five countries with the largest numbers of Labrador registrations are the United Kingdom, France, the United States, Sweden and Finland.