RPS6KA1 and glioblastoma: AZD-9291 monotherapy reduced the phosphorylation levels of EGFR, c-raf, MEK1/2, ERK1/2, and p90RSK in GBM cells, without affecting the phosphorylation levels of AKT, mTOR, p70S6, and 4E-BP1 in the AKT/mTOR signaling pathway, which were consistent with the conclusions of our previous study (Fig. 3C, D).