White blood cells generally play a protective role, capable of engulfing bacteria to prevent the occurrence of diseases.

White blood cells can also participate in the immune response of the body, for example, lymphocytes, traveling between tissue fluid, blood, and lymph, exerting a relatively strong resistance, and to some extent, they can also play an antibacterial infection role. When the body has an infection or a local infection, there may be an increase in neutrophils.

Because white blood cells can move flexibly, grow rapidly, and are the most basic protective mechanism of the human body, for example, when external bacteria and viruses invade the body, white blood cells will respond quickly, and to some extent, they can also engulf bacteria and viruses, which is helpful for protecting the health of the human body.