Since dendritic cells (DC) are important in regulating T cell responses, we determined PDL1 and PDL2 expression on CD141+ and CD141- myeloid (mDCs) and CD303+ plasmacytoid dendritic cells (pDCs), as well as on plasma cells (PC) in the blood and bone marrow in groups of patients with MGUS (monoclonal gammopathy of undetermined significance) and multiple myeloma. Here, CLEC4C is linked to plasma cell myeloma.