In NSCLC patients, mutually exclusive oncogenic K-Ras mutations and epidermal growth factor receptor mutations or amplifications occur in ∼30% and 10–40%, respectively, whereas inactivating, mostly missense, mutations in the p53 tumor suppressor are found in >50% of cases (Ding et al, 2008; Greulich, 2010). The gene discussed is KRAS; the disease is non-small cell lung carcinoma.