EGFR and neoplasm: In our study, concurrent sensitive and resistant somatic mutations in EGFR gene were the most frequently detected Co-SMs in lung adenocarcinoma, in which L858R + T790M or Exon19 deletion + T790M were frequently detected in patients with refractory NSCLC rather than in untreated naive patients; this result was consistent with the knowledge that most of the secondary EGFR-TKIs resistance are correlated with emerging EGFR T790M-positive tumor clones in NSCLC.