AKT1 and central nervous system cancer: A series of studies have shown that circRNAs can facilitate glioma tumorigenesis and progression by regulating the circPIP5K1A/miR-515-5p/TCF12/PI3K/AKT and circ0000215/miR-495-3p/CXCR2/PI3K/AKT pathways200,202 (Fig. 3).