Supporting evidence for this hypothesis came from studies conducted by Samuelsson et al. (11), Siragam et al. (12), and Kaneko et al. (13), who could show that FcγRIIB expression is required for a response to IVIg infusion in murine models of ITP, arthritis, and nephritis, respectively. This evidence concerns the gene FCGR2B and arthritic joint disease.