They may attack cells that might form tumors. Inflammatory Response Damage to tissue by physical injury will trigger an inflammatory response. Small blood vessels in the area will dilate and become leakier. This causes the redness and heat of the infected area. This enhances the migration of phagocytes into the area.
Neutrophils arrive first, followed by monocytes that develop into macrophages.
Clotting proteins seal off the infected area. Sometimes white blood cells release chemicals called pyrogens. They act on the bodies thermostat and raise the temperature in an effort to kill the microorganism. Acts in warning other cells of a viral invasion. It is produced by infected cells.