Answer:
immune tolerance
Step-by-step explanation:
The term immunological tolerance refers to a specific non-reactivity state for a given antigen, and is induced by prior exposure to that antigen. Tolerance may be induced for non-self antigens, but the most important aspect of tolerance is self-tolerance, which prevents the organism from making an attack against its own constituents. The potential for self-harm arises because the immune system generates a large, haphazard diversity of antigen-specific receptors, some of which will become self-reactive. Cells carrying these receptors must be functionally or physically deleted.