Badie et al. demonstrated in vitro that glioma-derived HGF/SF is a potent chemotactic agent on microglia [61] postulating that tumor-secreted HGF/SF acting upon TAM c-Met receptors may be a major mechanism by which glioma tissue recruits monocytes to commandeer toward the construction of a favorable microenvironment. This evidence concerns the gene HGF and central nervous system cancer.