NCAM1 and POEMS syndrome: Five (55.6%) were CD19−/CD56+ and three (33.3%) were CD19−/CD56− in MM-flow (Fig. 2A), whereas five (27.8%) were CD19−/CD56+ and 12 (66.7%) were CD19−/CD56− in POEMS-flow (Fig. 2B), indicating that the immunophenotype of monoclonal PCs in POEMS syndrome was similar to that in MM.