Based on the critical role of neutrophils in EBA pathogenesis (47, 56–58) and the results of our in vitro data analyzing the C5a and Fcγ receptor-mediated activation of neutrophils, we hypothesized that a deficiency of C5ar2 in neutrophils is the leading cause for the ameliorated disease phenotype. The gene discussed is C5AR1; the disease is acquired epidermolysis bullosa.