FcγRIIA is a specific receptor for immunoglobulin G (IgG), belonging to the family of Fcγ receptors (FcγR). Among the FcγRs, FcγRIIA functions as an activating receptor. This receptor is primarily expressed on the membranes of immune cells, such as human platelets, and serves as a bridge between specific antibodies and effector cell functions, tightly linking humoral immunity with cellular immunity. FcγRIIA plays a crucial role in regulating IgG effects, as it can bind to monomeric and immune complex (IC) IgG. It can induce either activation or inhibition of functions, participating in driving antibody effector functions such as antibody-dependent cell-mediated cytotoxicity (ADCC) and/or antibody-dependent cellular phagocytosis (ADCP), as well as antigen presentation and the release of chemokines and cytokines. In autoimmune inflammatory diseases like systemic lupus erythematosus (SLE), the expression of FcγRIIA may exacerbate lupus nephritis and promote platelet activation.