Indeed, adipocyte-derived factors such as monocyte chemoattractant protein 1 (MCP-1) and stromal cell-derived factor 1 (SDF1) are known chemotactic factors for myeloma cells (9, 23), whereas other factors promote myeloma proliferation (e.g., leptin) (10) and resistance to chemotherapies (e.g., leptin and adipsin) (11). Here, CXCL12 is linked to plasma cell myeloma.