Macrophage is a large phagocytic cell found in stationary form in the tissues or as a mobile white blood cell, especially at sites of infection, it is a type of white blood cell that engulfs and digest cellular debris and foreign materials. Macrophage is key players in the immune response to foreign invaders of the body, such as infectious microorganisms. They are normally found in the liver, spleen, and connective tissues of the body.
Macrophages are important cells of the immune system that are formed in response to an infection or accumulating damaged or dead cells. Macrophages are largfe, specialized cells that recognize, engulf and destroy target cells. The term macrophage is formed by the combination of the Greek terms "makro" meaning big and "phagein" meaning eat. Macrophages are formed through differentiation of monocytes, one of the major groups of white blood cells of the immune system.