Macrophage and cancer cells.Composition coloured scanning electron micrograph (SEM). Macrophages (white) offer help in the fight against cancer. There are two types of these cells M1 and M2 macrophages and they both serve complementary roles.M1 macrophages activate the immune system, telling it to start fighting, while M2 cells soothe the ensuing inflammation. Cancer has a double-edged strategy of getting past the macrophages' vigilant eyes. firstly it turns the combative M1 macrophages into peaceful M2 macrophages, and secondly malignant cells emit a don't eat me signal that tricks M1 cells into leaving. However, current research, might have found a way to outfox cancer's clever ways, defeating both of its mechanisms in one knockout blow, activating macrophages that can eat cancer cells. Magnification: x8000 when printed at 10 centimetres wide.