KRAS and non-small cell lung carcinoma: In example, while mutations in the EGFR tyrosine-kinase domain are mutually exclusive with KRAS mutations and are positive predictive biomarkers for the efficacy of tyrosine kinase inhibitors in non-small cell lung cancer (NSCLC) (34, 47), these mutations are rare and scarcely relevant in predicting responses to antibody-based anti-EGFR therapy, in mCRC (48).