EML4 and non-small cell lung carcinoma: Here we report a multiple metastatic NSCLC patient who was detected to have pure EGFR 19 exon deletion (negative for EML4-ALK and ROS1 in both IHC-based and sequencing assay) in the primary lesion and responded to first-line and second-line EGFR-TKI treatments (erlotinib then HY-15772).