In blood samples from 297 patients with non-small cell lung cancer, the positive rate of EML4-ALK detected by next-generation sequencing was 3.70% (11/297), the mutation rate of adenocarcinoma was 3.82% (10/262), and the mutation rate of squamous cell carcinoma was 2.86% (1/35). The gene discussed is EML4; the disease is adenocarcinoma.