Natural selection on marine carnivores elaborated a diverse family of classical MHC class I genes exhibiting haplotypic gene content variation and allelic polymorphism.
Hammond JA, Guethlein LA, Norman PJ, Parham P. Natural selection on marine carnivores elaborated a diverse family of classical MHC class I genes exhibiting haplotypic gene content variation and allelic polymorphism. Immunogenetics. 2012 Dec; 64(12):915-33.