What is the role of white blood cells in the immune system?

White blood cells can have different roles and are important for protecting the body against pathogens. They can ingest a pathogen and destroy it, some produce antitoxins which destroy the toxins produced by the pathogen, and they may produce antibodies which attach to the pathogen to destroy it. Antibodies are specific to pathogens, so different types of pathogen require a different antibody in order to be destroyed. Once a particular antibody has been produced, the immune system will remember it, so if the body is infected again it will be able to quickly produce the correct antibody.