Fig. 1

A subset of EGFR-mutated NCLC cells is highly resistant to icotinib. A Growth-inhibitory effects of indicated time and doses of icotinib were determined via CCK-8 assays, IC50s are depicted. B Clonogenic assays detected the response of EGFR-mutated NSCLC cells to icotinib. C Cell apoptosis induced by icotinib was displayed by flow cytometry analysis (Annexin V-7-AAD staining in the x-axis and PI in the y-axis). D Cleaved Caspase-3 and Cleaved PARP known as the markers of apoptosis were measured using immunoblotting assays. [In line charts, **P < 0.01, ***P < 0.001 as compared with the control group. In bar charts, **P < 0.01, ***P < 0.001 as compared with the 24 h group, ##P < 0.01vs. the 48 h group, §§ P < 0.001 as compared with the 72 h group]