The mammalian equivalent to bursa Fabricii of birds.
D000818:Animals; D005075:Biological Evolution; D002060:Bursa of Fabricius / Q000502:physiology*; D006801:Humans; D007109:Immunity; D008322:Mammals; D010828:Physiology, Comparative; D013950:Thymus Gland / Q000502:physiology*