CXCL12 and neoplasm: For instance, IL-6, CCL-25, SDF-1, and CXCL16 secreted by breast cancer, multiple myeloma, osteosarcoma, and prostate cancer cells promote MSC migration toward the tumor microenvironment respectively.9 Further, cancer-related immune cells secrete pro-inflammatory cytokines IL-1β and TNF-α that exert critical roles in the migration toward and differentiation within the tumor microenvironment.10