CXCR4 and cancer: Additionally, both kinds of glia-induced cancer cell invasion were significantly inhibited by the WNT-inhibitor DKK2 as well as by AMD3100, a CXCR4 inhibitor (Fig. 6G) without cytotoxicity either to the epithelial cells, MCF-7 and MDCK, or the glia cells, microglia and astrocytes (Supp.