A substance the immunity perceives to be foreign or dangerous. The body combats an antigen with the production of an antibody.
"compound which causes production of an antibody," 1908, from German Antigen, from French antig
Any compound or item the human anatomy of an animal would respect as strange or undesirable; a foreign condition or virus in your body (toxin, etc.)
any substance (as a toxin or chemical) that promotes an immune reaction in the torso (especially producing antibodies)
a foreign agent effective at starting an immune response or evoking the human body to produce antibodies. a substance that when introduced in to the body stimulates the production of an antibody. Antigens feature toxins, micro-organisms, viruses, fungi, international bloodstream cells, in addition to cells of transplanted organs. Also called allergen or immunogen.
The molecules which lead to the production of anti-substances are usually known as antigens, and each antigen has a specific combining affinity for its corresponding anti-substance, fitting it as a lock does a key.