EGFR and non-small cell lung carcinoma: As a third-generation EGFR TKI highly selective for EGFR-activating mutations, OSI is not only approved for the treatment of T790M-positive patients who have progressed on first- or second-generation EGFR-TKIs, but also as first-line therapy for advanced EGFR-mutated NSCLC, regardless of T790M mutation status (Soria et al., 2018; Yi et al., 2019).