RRM1 and small cell lung carcinoma: Also, Ceppi et al, quantified ERCC1, RRM1, and TOPOII mRNA expression in 85 SCLC patients treated with platinum/etoposide [33]; they found that TOPOII expression was associated with better response in LS-SCLC patients, while patients of the same stage of disease and low ERCC1 mRNA levels had significantly longer survival.