FGFR4 and metastatic colorectal cancer: At the pathway level, we detected that the alteration rate (mutation and copy number variation) of the genes involved in MAPK signaling pathways, including FGFR1, FGFR2, FGFR3, FGFR4, BRAF, and MEK, was significantly lower in metastatic colorectal cancer tissue compared to the primary site.