FCGR2B and autoimmune disease: Based on the cell types expressed and their roles in immune responses, many efforts have been made to clarify the therapeutic efficacy of targeting FcγRIIb in autoimmune diseases and hematopoietic cancers (Nakamura et al., 2000; Boross et al., 2011; Li and Ravetch, 2011; Roghanian et al., 2015).