ERCC1 and non-small cell lung carcinoma: In the univariate analysis model of survival, RRM1, ERCC1, and BRCA1 expression levels in peripheral blood (normalized to β-actin expression) of 34 NSCLC cases were divided into low-expression and high-expression groups, where the boundary was defined by the median (median RRM1, ERCC1, and BRCA1 expressions were used as the cutoff values).