In this study, we show that a) our single-tube 10-color MFC panel was reliable for MRD detection in the whole spectrum of monoclonal gammopathies (MGUS, SMM, and MM) with a consistently high sensitivity, b) the additional markers included in this panel, prominently CD81 and CD200, were valuable and informative for MRD detection, while in select cases kappa/lambda proved beneficial, and c) MRD assessment was possible in apheresis samples likewise to BM, with MRD apheresis status holding predictive value for responses after ASCT. The gene discussed is CD200; the disease is Miyoshi myopathy.