Strategy of flow cytometry analysis of immunostained whole blood and marrow samples (from MGUS and MM patients). Gating was done sequentially on live cells, on lineage-negative cells, and then on CD11c⁺HLA-DR^hi cells or BDCA-1/BDCA-3⁺HLA-DR^hi cells to identify mDCs and on CD123⁺HLA-DR⁺ cells or BDCA-2⁺HLA-DR⁺ to identify pDCs. Representative plots from 1 patient for each group.