Prior work reported that cfDNA‐NGS test was applicable and useful in ALK positive NSCLC patients,17, 18, 19, 20, 21, 22 but the small number of patients studied still remain a limitation to determine the predictive role of cfDNA‐NGS in the ALK positive NSCLC patients who were being treated with TKI. This evidence concerns the gene ALK and non-small cell lung carcinoma.