PATHOLOGY

Detailed explanation-1: -Any substance that causes the body to make an immune response against that substance. Antigens include toxins, chemicals, bacteria, viruses, or other substances that come from outside the body. Body tissues and cells, including cancer cells, also have antigens on them that can cause an immune response.

Detailed explanation-2: -Antigens are substances (usually proteins) on the surface of cells, viruses, fungi, or bacteria.

Detailed explanation-3: -Antigen An antigen is a nonself substance that can mobilize the adaptive defenses and provoke an immune response.

Detailed explanation-4: -Antigens are any substances that the immune system can recognize and that can thus stimulate an immune response. If antigens are perceived as dangerous (for example, if they can cause disease), they can stimulate an immune response in the body.