Model of FcγRIIIA and FcγRIIIB function in PMNs. Model of CD16A and CD16B activities in PMN function in FcγRIIIB WT donors (A) and the FcγRIIIB-null individual (B). FcγRIIIA plays a major role in PMN activation (measured as CD11b induction) and phagocytosis. FcγRIIIB is very abundant on FcγRIIIB WT PMNs and has a role in binding ICs favoring trogocytosis. In the absence of FcγRIIIB, trogocytosis takes place primarily via FcγRIIA.