...We analyzed the initial tissue upon which was only found EGFR p.E746_S752delinsV by next-generation sequencing...the patient was administrated erlotinib (150 mg daily) from November 2014 to August 2017. Thus far, no progression of the original lung mass has been identified; however, multiple bone, liver, and adrenal metastases were noted...Hence, we concluded that the patient had EGFR–tyrosine kinase inhibitor (TKI) resistance.