MAP kinase activation is mediated by PI3K pathway in CHO cells (Galve-Roperh et al., 2002), PC-3 cells (Sánchez et al., 2003) and astrocytoma cells (Gómez del Pulgar et al., 2000), through the protein kinase B (PKB/Akt) phosphorylation and Raf-1 activation. Here, AKT1 is linked to astrocytoma (excluding glioblastoma).