Every second, a war is being waged inside us, between specialized cells of our immune system and a host of “enemies” that include viruses and malicious bacteria. At the center of this action are macrophages, from the Greek word which means“big eaters”. And that’s why they are. Macrophages are a type of white blood cells of the immune system whose role is to engulf and digest cellular debris, microbes, cancer cells and anything else that are disagreeable to healthy body cells in a process called phagocytosis. Besides phagocytosis, they play a critical role in nonspecific or what is called innate immunity, that part of an organism’s immune system that is relatively nonspecific and can therefore provide a rapid response to all manner of intracellular pathogenic invasions. Sounds Greek to you? Here’s a video clip to help you visualize what’s going on in the “battlefield”. The clip is developed by scientists at Leiden University led by Professor Annemarie Meijer using advanced imaging technology. Watch how the macrophages surround, then absorb the E. coli bacteria.