The Japanese guidelines for colorectal cancer treatment and the National Comprehensive Cancer Network (NCCN) Clinical Practice Guidelines in Oncology for Colon and Rectal Cancers recommend systemic administration of l-leucovorin, 5-fluorouracil, irinotecan, oxaliplatin, bevacizumab, and anti-epidermal growth factor receptor (EGFR) antibody for unresectable or recurrent colon cancer[1]. This evidence concerns the gene EGFR and cancer.