> The only answer that I know is a functional one - an antigen is any substance
> which can elicit an immune response.
>> BioKen
> --
Is not the "immunogen"/"antigen" distinction a valid one? Thus, an
"immunogen" is what you defined, while an "antigen" is something which can
be recognized by any protein component of the immune system, whether or
not it is immunogenic. The definitions are still functional, but one can
distinguish between those substances which can still interact with an
antibody, TCR,etc., but are incapable of inducing an immune response.
John
