Previous clinical studies have shown that lung cancer patients with low levels of RRM-1 mRNA are more sensitive to gemcitabine and have longer survival times [26–28] and the recent US National Comprehensive Cancer Treatment Access Coalition (NCCN) NSCLC treatment guidelines recommend measurement of RRM-1 expression before implementation of gemcitabine therapy in NSCLC patients [29]. The gene discussed is RRM1; the disease is non-small cell lung carcinoma.