Cancer-associated fibroblasts (CAFs) are abundant stromal cells in the tumor microenvironment, they secrete cytokines such as HGF, IL-6, and SDF-1, which have a variety of effects on cancer cells and stroma1–8, including angiogenesis, tumor growth, migration, and are an alternative for extracellular matrix. The gene discussed is CXCL12; the disease is neoplasm.