In PTEN-deficient U87MG glioma cells, PtdIns(3,4)P2 production predominantly depends on the high PtdIns(3,4,5)P3 accumulation, according to a study using a high-avidity biosensor of PtdIns(3,4)P2 [62], which is distinct from class II PI3K-driven PtdIns(3,4)P2 production from PtdIns(4)P during clathrin-mediated endocytosis [34]. This evidence concerns the gene PTEN and central nervous system cancer.