EGFR and cancer: We first screened a panel of NSCLC cancer cell lines and found that only mutant EGFR-expressing cell lines, such as H3255 (EGFR L858R, GI50: 0.11 μM), PC-9 (EGFR Del 19, GI50: 0.05 μM), and HCC827 (EGFR Del 19, GI50: 0.063 μM), are sensitive to ibrutinib treatment.