CCL2 and plasma cell myeloma: Of the top highly upregulated genes, we observed that the expression of four chemokines or cytokines, macrophage C-X-C motif ligand (CXCL)1, CXCL2, stromal cell-derived factor 1 (SDF1), and monocyte chemoattractant protein 1 (MCP1), were upregulated in myeloma cells cocultured with MSCs.