KRAS and neoplasm: Some studies describe a more favorable clinical outcome in patients with CRC with a KRAS A146-mutated tumor upon anti-EGFR treatment compared with patients with tumors carrying another KRAS mutation.54-57 Other studies show that tumors with a KRAS A146 mutation, like other KRAS mutations, are responsible for anti-EGFR resistance.58-61In this study, the homogenous population of initially unresectable liver-only metastatic CRC patients all receiving the same treatment regimen allowed for an unbiased comparison of the clinical features of patients harboring different KRAS tumor mutations.