Evaluation of the effects of HDN-1 on three NSCLC cell lines expressing wild type EGFR (A549), exon 19 deletions EGFR (HCC827), or T790M EGFR (H1975) showed that HDN-1 exhibited stronger inhibitory activity in the two cell lines with EGFR mutation than the cells with wild type EGFR. The gene discussed is EGFR; the disease is non-small cell lung carcinoma.