Explain the following statement "the essence of the immune system is the ability to recognize 'self' from 'non-self'.”

"the essence of the immune system is the ability to recognize 'self' from 'nonself'.”Immunotolerance

Explanation:

The ability of an immune system to recognize self and non-self antigens. This is an important feature that enables the immune system to avoid auto-attacking self tissues thus preventing autoimmunity. The immune system has the ability to recognize self from non-self.

The immune system is self tolerant during lymphocyte development and T regulatory cells( Tregs) are critical in the maintenance of auto-tolerance.

i believe it is "they are not used up by reactions" as the answer to your question, text me back if this is correct because i just learned this.