Almost all patients were refractory or intolerable to standard front-line chemotherapeutic agents (fluoropyrimidine, oxaliplatin and irinotecan; 100%, bevacizumab; 99%, anti-epidermal growth factor receptor (EGFR) antibody; 88%, KRAS or RAS wild-type tumour), whereas only 22% of the patients had previously received TAS-102. This evidence concerns the gene KRAS and neoplasm.