Bone marrow stromal cells (BMSCs), osteoclasts (OCs), and plasmacytoid dendritic cells (pDC), as well as cytokines, i.e., interleukin-6 (IL-6), Macrophage colony-stimulating factor (M-CSF), interleukin-10 (IL-10), tumor necrosis factor beta (TGFβ), C-C Motif Chemokine Ligand 2 (CCL2), and vascular endothelial growth factor (VEGF), also play important roles in maintaining an immunosuppressive environment in the bone marrow of multiple myeloma patients [25,27]. Here, CCL2 is linked to plasma cell myeloma.