Microglia/macrophage are able to infiltrate in the tumor mass in response to chemoattractive cytokines released by the tumor, such as colony-stimulating factor (Imai and Kohsaka, 2002), fractalkine (Held-Feindt et al., 2010), and VEGF (Forstreuter et al., 2002). Here, CX3CL1 is linked to neoplasm.