AKT1 and central nervous system cancer: The blockade of PI3K/AKT signal also inhibited the collagen/FN cultured glioma cell proliferation (Figure 3D and Figure S3D), colony formation (Figure 3E and Figure S3E), and tumorigenesis (Figure 3F and S3F), indicating the crucial role of PI3K/AKT signaling in glioma cells cultured in the 3D collagen/FN system.