What is the name for any substance that stimulates the production of antibodies?

An antigen is any substance that triggers an immune response, specifically stimulating the production of antibodies. When the immune system detects an antigen, it responds by producing specific antibodies that target the antigen for destruction or neutralization. This process is crucial for the body’s defense against infections and diseases.

In contrast, enzymes are biological catalysts that speed up chemical reactions but do not directly involve the immune response. Pathogens refer to harmful microorganisms like bacteria, viruses, fungi, and parasites that can cause disease, and while they can also be antigens, the term itself does not specifically denote the substance responsible for antibody production. Toxins are poisonous substances produced by organisms that may cause harm, but they, too, do not specifically refer to the molecules stimulating antibody production. Therefore, the term 'antigen' accurately describes substances that provoke antibody responses in the immune system.