{"type":"root","children":[{"type":"paragraph","children":[{"type":"text","value":"CD16 is a low affinity Fc receptor, found on the surface of natural killer cells, neutrophil polymorphonuclear leukocytes, monocytes and macrophages. CD16 has been identified as Fc receptors FcγRIIIa (CD16a) and FcγRIIIb (CD16b). These receptors bind to the Fc portion of IgG antibodies which then activates NK cells for antibody-dependent cell-mediated cytotoxicity. A lack of CD16 in a given population of neutrophils may indicate prematurity, as could be caused by a left shift due to neutrophilic leukocytosis induced by tissue necrosis or bacterial infection."}]}]}