A, The given cell lines were exposed to DMSO and 50 nM (PC-9), 100 nM (HCC827) or 250 nM (H1975 and H1650) osimertinib (Osim), respectively, for the different times as indicated. Western blotting was used to detect different proteins. B-E, The indicated cell lines plated in 96-well plates were exposed to varied concentrations of osimertinib alone, trametinib (Tram) or VRT52271 (VRT) alone or their respective combinations. After 3 days, cell numbers were estimated using the SRB assay. The data are means ± SDs of four replicate determinations. The numbers inside the graphs are CIs for the given combinations.