Previous studies have reported the association between ERCC1, BRCA1, RRM1 and RRM2 and NSCLC prognosis.9,11-13 However, the results are inconsistent.9,11-13 Therefore, we conducted this prospective study to investigate the role of mRNA expression quantities of ERCC1, BRCA1, RRM1 and RRM2 in NSCLC patients, and investigate their association with response to chemotherapy and clinical outcome of advanced NSCLC. The gene discussed is ERCC1; the disease is non-small cell lung carcinoma.