Antigen: Foreign substance in the Body that induces an immune response. The antigen stimulates lymphocytes to produce antibodies or to attack the antigen directly (see antibody;immunity).

• 抗原:一种外来物质,当其进入体内时,能附着于淋巴球表面而引发特定免疫反应。淋巴球被活化后,能制造抗体或直接攻击抗原;此种能够引发免疫反应的抗原,我们称之为免疫原。