What is antiegen?

An antigen is a molecule that is capable of inducing an immune response in the body, typically by interacting with specific receptors on immune cells such as T cells and B cells. Antigens can be proteins, carbohydrates, lipids, or nucleic acids, and are often derived from foreign substances like pathogens or non-self cells. The immune system recognizes antigens as "non-self" and mounts a response to eliminate them from the body.