Moreover, pro-gastrin releasing-peptide (pro-GRP) during EGFR-TKI treatment is also an indication of transformation from NSCLC to SCLC.[18–20] However, little attention has been paid to the NSE and pro-GRP levels in serum, as there are no routine clinical tests for NSCLC patients. This evidence concerns the gene EGFR and non-small cell lung carcinoma.