The body recognizes antigens as foreign substances, and when they are identified, the body initiates an immune response.
Receptors on white blood cells bind to the antigens, which then trigger the multiplication of white blood cells and initiate an immune response, namely the creation of antibodies. One type of white blood cell, B cells, can create antibodies when attached to an antigen. The antibodies can then fight that particular antigen whenever they come into contact with it, even years later.
Antigens are also a significant part of healthcare in regard to identifying illnesses and protecting the body from them. For example, vaccines are used to initiate the body’s immune response against a particular antigen and create antibodies.
Additionally, some diagnostic tests use antigens as markers to identify the body tissues and cells with antigens on them, such as cancer cells.