EGFR and non-small cell lung carcinoma: Currently a study called “APPLE trial” (ClinicalTrials.gov identifier: NCT02856893) has been designed to evaluate the best sequential treatment strategy with gefitinib and osimertinib in advanced EGFR mutation-positive NSCLC patients, and to understand the value of plasma ctDNA T790M test as a predictive marker for making treatment decisions [40].