[{"Bold_text": "noun", "List Items": ["Immunology.any substance, as a protein, carbohydrate, etc., that, on entering the body, can stimulate an immune response and combine with a specific antibody or T cell receptor having a matching molecular structure.", "Pharmacology.any commercial substance, usually synthetic, that stimulates the production of antibodies injected or absorbed into animal tissues.", "antigens of a particular type collectively."]}]