- An antigen that is found in more than one species. An antigen is something that is capable of inducing an immune response. The prefix "xeno-" means foreign or other. It comes from the Greek "xenos" meaning stranger, guest, or host.
* * *xeno·an·ti·gen (zen″o-anґtĭ-jən) an antigen occurring in organisms of more than one species, e.g., the A and B antigens of the ABO blood group.
Medical dictionary. 2011.