The concomitant KRAS and BRAF mutations occurrarely in the colorectal cancers (CRCs) with the prevalence of less than 0.001% of the cases.In patients with KRAS-mutant tumors, BRAF mutations should not regularly be testedunless the patient is participating in a clinical trial enriching for the presence of KRAS orBRAF-mutated tumor. This evidence concerns the gene BRAF and colorectal cancer.