In this study, by employing a single cell manipulation tool and direct preparation of recombinant Abs [27,28] coupled with novel high-throughput cell-based binding assays, we successfully analyzed the anti-AChR Ab repertoire derived from individual peripheral B cells of patients with MG and isolated a pathogenic Ab which can be a molecular target for MG therapy in human. This evidence concerns the gene DDX41 and myasthenia gravis.