Figure 2.

The pros and cons of immune activation. The activation of the immune system plays a vital biological function in the body. The pros of immune activation include immune defense response to foreign pathogenic microorganisms, immune surveillance response to tumors and aging factors, and immune tolerance to non‐harmful substances, self‐proteins and peptides, etc. However, most of the damage caused by immune activation is related to the destruction of immune tolerance, such as overreaction to non‐harmful substances and a persistent inflammatory state in the body.