KRAS and lung adenocarcinoma: We identified 60 lung adenocarcinomas from individual patients with tumors shown to be sensitive or refractory to single-agent gefitinib or erlotinib and evaluated these tumors for mutations in EGFR and KRAS. Collectively, nine of 38 (24%) tumors refractory to either kinase inhibitor had KRAS mutations, while zero of 21 (0%) drug-sensitive tumors had such mutations (p = 0.02) (Table 1).