FCGR2B and acquired epidermolysis bullosa: To the best of our knowledge, this is the first report on the role of FcγRIIB in an active model of EBA, in which congenic FcγRIIB-deficient and wt mice with the same disease-permitting H2s haplotype (B6.s background) have been compared side-by-side regarding the impact of FcγRIIB on the B and the effector cell responses.