Cytokines and growth factors contained in platelet alpha or dense granules can act as tumor-promoting signals and play a variety of roles in the tumor microenvironment, including promoting invasion and metastasis through active regulation of epithelium to mesenchyma [39, 98, 99], such as vascular endothelial growth factor (VEGF), epidermal growth factor (EGF), platelet-derived growth factor (PDGF), transforming growth factor β (TGF β), interleukin-1β (IL-1β), IL-8, and CXC-containing ligand 12 (CXCL12) [100–103]. The gene discussed is CXCL12; the disease is neoplasm.