Previous studies have indicated that the effectiveness of anti-EGFR antibody treatment in patients with BRAF-mutated colorectal cancer is lower than that in patients with wild-type BRAF. However, this effect was not detected in the subgroup with MAPK-activating mutations in BRAF or RAS mutations because the anti-EGFR antibody inhibits the MAPK pathway activated by EGFR25. Here, EGFR is linked to colorectal cancer.