In vivo tumorigenesis, we found that FGFR4 promotes tumor growth and high expression of AREG in xenograft tumors. FGFR4 expression reduced the sensitivity to cetuximab in colon cancer cells and synergistic effect was shown when treated with FGFR4 inhibitor with cetuximab. A positive correlation between FGFR4 and AREG expression was observed in cancer, but not in normal tissues and high FGFR4 or AREG expression showed significantly inferior overall survival than low expression in patients treated with cetuximab for metastatic colon cancer.