This volume provides a state-of-the-art update on Fc Receptors (FcRs). It is divided into five parts. Part I, Old and New FcRs, deals with the long-sought-after FcµR and the recently discovered FCRL family and TRIM21. Part II, FcR Signaling, presents a computational model of FceRI signaling, novel calcium channels, and the lipid phosphatase SHIP1. Part III, FcR Biology, addresses major physiological functions of FcRs, their glycosylation, how they induce and regulate both ada