EGFR and non-small cell lung carcinoma: In contrast, NCI-H1975, a cell line derived from an EGFR-TKI-naïve NSCLC patient that intrinsically harbors an EGFR-T790M gatekeeper mutation in the ATP-binding pocket in addition to an activating mutation (L858R) [36], was resistant to gefitinib and erlotinib (Figure 2B and 2C), as reported previously [37].