Leukocyte trafficking refers to the movement of white blood cells throughout the body, which is essential for the immune response. These cells travel through the bloodstream and migrate to tissues where they are needed, such as sites of infection or inflammation. This process is guided by various signals, including chemical signals called chemokines that attract leukocytes to specific areas. The trafficking of leukocytes involves several steps, including rolling along the blood vessel walls, adhesion, and eventual migration through the vessel walls into the surrounding tissue. This coordinated movement ensures that the immune system can effectively respond to threats, maintaining the body's health and defense mechanisms.