The white blood cells which are involved in the detection, phagocytosis and destruction of harmful organisms such as bacteria are termed as macrophages. Anything within the body which does not have the proteins on its surface which are found in healthy human cells are digested by these cells. Some of the harmful organisms and cells digested by macrophages are cancer cells, microbes and foreign substances. The cells which are responsible for processing antigen material and presenting it to the T cells of the immune system on the surface of the cell are termed as dendritic cells. Macrophages, dendritic cells and monocytes together make up the mononuclear phagocyte system. This book contains some path-breaking studies on macrophages and dendritic cells. It consists of contributions made by international experts. This book will serve as a valuable source of reference for graduate and post graduate students.