It should also be appreciated that the cellular expression levels and receptor diversity as will be described later is also influenced by the activation state of the cells, anatomical location and the cytokine environment which modulates FcγR expression, particularly for FcγRI and FcγRIIb.18 For example, resting monocyte subpopulations may express only FcγRIIa but activated macrophages express FcγRI, FcγRIIa and FcγRIIIa and/or FcγRIIb.7