Which of These Best Describes an Antigen

Question

Which of these best describes an antigen?
A)A receptor on an immune cell.
B)An immune receptor that binds to a ligand.
C)Any component that can be specifically bound by an immune receptor.
D)Any type of ligand.
E)Any type of immunogen.

Accepted Answer

An antigen is any component that can be specifically bound by an immune receptor, such as an antibody or T cell receptor. This can include proteins, carbohydrates, lipids, and nucleic acids, as well as foreign substances like bacteria and viruses.

Answer: E 
 While an antigen is specifically defined as a component that can be recognized by an immune receptor, an immunogen is a substance that can elicit an immune response, such as the production of antibodies or activation of T cells. Not all antigens are immunogens, but all immunogens are antigens.