The Fc-GammaRs (Fc-Gamma Receptors/Immunoglobulin-Gamma Fc Receptors) expressed on hematopoietic cells play a key role in immune defenses by linking humoral and cellular immunity. Fc-GammaRs display coordinate and opposing roles in immune responses depending on their cytoplasmic region and/or their associated chains (Ref.1). These receptors recognize the Fc (Crystalline Fragment) domains of IgGs (Immunoglobulin-G), and play a crucial in vivo role in both initiation and regulation of inflammatory and cytotoxic responses, and also in the process of Phagocytosis in phagocytic cells: Macrophages, Neutrophils, and Monocytes (Ref.2). These Fc-GammaR-mediated immune responses can be exploited to develop novel immunotherapies. There are two major classes of Fc-GammaRs: Activation Receptors/Activating Receptors (receptors that activate effector functions) and Inhibitory Receptors (receptors that inhibit these functions). The [...]