A toxin or other foreign substance that induces an immune response in the body, especially the production of antibodies
Any of the red blood cell antigens constituting the rhesus blood group system; especially the major (D) antigen of this system.
Any of the cell-surface antigens involved in the determination of histocompatibility; especially any antigen of the major histocompatibility complex (the HLA system in humans and H-2 system in mice).
An antigenic enzyme released by the prostate and found in abnormally high concentrations in the blood of men with prostate cancer
Any cell that assists in the production of immune responses by presenting antigen; especially any of several types of cell with monocytic lineage that present antigen in association with class II MHC molecules, to helper T lymphocytes.