GFAP and central nervous system cancer: Considering the reports that growth factor mediated activation of RAS pathway causes an activation of PI3-kinase [20], and that a combined activation of RAS-MAP-kinase and PI3-kinase-AKT pathways are critical for the pathogenesis of glioblastoma [21], we hypothesized that the attenuation of PI3-kinase/AKT signaling will be effective in regulating the tumorigenic phenotypes (proliferation and integrin-mediated migration) of the glioma cells derived from GFAP-12 V-Ha-Ras transgenic mice.