Using the GAL4-UAS system in Drosophila, we have established a glioma model by coactivation of the PI3K and MAPK pathways [by downregulation of Pten (UAS-PtenRNAi) and overexpression of oncogenic Ras (UAS-RasV12)] in the glial cells (Repo-GAL4) of the larval CNS (Waghmare et al., 2014; Cheng et al., 2016). The gene discussed is PTEN; the disease is central nervous system cancer.