Can antigens trigger a response of the immune system?

Yes, antigens can trigger a response of the immune system.

An antigen is a molecule that the immune system recognizes as foreign or potentially harmful. When an antigen enters the body, the immune system responds by producing antibodies and other immune cells that can bind to and destroy the antigen. This process is called the immune response.

There are two types of antigens: exogenous and endogenous. Exogenous antigens are molecules that come from outside the body, such as bacteria, viruses, and pollen. Endogenous antigens are molecules that are produced inside the body, such as cancer cells and proteins that are associated with autoimmune diseases.

Both exogenous and endogenous antigens can trigger an immune response. However, the type of immune response that is triggered will depend on the type of antigen and the state of the immune system.