Furthermore, reduced let-7 gene expression in NSCLC patients is correlated with poor prognosis (Takamizawa et al, 2004; Yanaihara et al, 2006), and a single nucleotide polymorphism in let-7 complementary site 6 of the K-RAS mRNA 3′-UTR is significantly associated with increased risk for NSCLC among moderate smokers (Chin et al, 2008). The gene discussed is KRAS; the disease is non-small cell lung carcinoma.