Innate immune cells
All white blood cells are known as leukocytes. Leukocytes differ from other cells in the body in that they are not closely associated with a particular organ or tissue; thus, their function is similar to that of independent unicellular organisms. Leukocytes are able to move freely and interact with and capture cellular debris, foreign particles and invading microorganisms. Unlike many other cells in the body, most leukocytes in the innate immunity system can not divide or reproduce by themselves, but are the products of multipotent hematopoietic stem cells present in the bone marrow.
Innate immune leukocytes include: natural killer cells, mast cells, eosinophils, basophils; and phagocytic cells include macrophages, neutrophils, and dendritic cells, and function in the immune system by identifying and eliminating pathogens that could cause infection.