Any antigen found in some but not all individuals of the same species; specifically any of two or more forms of an antigen coded for by alleles of the same gene.
Origin
1960s. From allo- + antigen.
Definition of alloantigen in US English:
alloantigen
nounˌaləʊˈantɪdʒ(ə)n
Immunology
Any antigen found in some but not all individuals of the same species; specifically any of two or more forms of an antigen coded for by alleles of the same gene.