(A) Dose-dependent effects of afatinib on apoptosis. Data are mean ± SD. n = 3 for each concentration. *, p < 0.05, **, p < 0.01, vs. no afatinib. (B) Dose-dependent effects of afatinib on DNA fragments. Data are mean ± SD. n = 3 for each concentration. *, p < 0.05, **, p < 0.01, vs. no afatinib. (C) Effects of afatinib on PARP in the four NSCLC cell lines. Cells were treated with afatinib at the indicated concentrations for 48 h. Data are representative of three independent experiments. (D) Effects of afatinib on caspase-3 activity. NSCLC cells were treated with afatinib at the indicated concentrations for 48 h. Data are mean ± SD. n = 3 for each concentration. *, p < 0.05, **, p < 0.01, vs. no afatinib.