Glioma and MSCs have been shown to secrete various factors, such as stromal cell-derived factor 1 (SDF-1, also known as CXCL12), VEGF, PDFG, endothelial cell growth factor (EGF), TGF-β1, interleukin 8 (IL-8), and the MCP1 protein, which contribute to tumor tropism [30,31,32,33]. The gene discussed is CXCL12; the disease is glioma.