2.3.2 Cells of the monocyte–macrophage lineage2.3.2.1 Monocytes and macrophagesMacrophages (and their precursors, monocytes) are the main phagocytic cells of the immune system. Tissue macrophages are present throughout the body and contribute to tissue homeostasis and immune surveillance. Upon tissue damage or infection, monocytes are rapidly recruited to the tissue where they differentiate into..