The levels of PI3K/mTOR signaling proteins, including pAkt, pS6 and P4EBP1 decreased in a dose- and time-dependent manner in all tested glioma cells (Figure 2A and 2B) as well as in the glioma tumor-initiating cell line GSC11 (Figure 2A and 2B). Here, PIK3CA is linked to central nervous system cancer.