To further confirm CD15/FUT4 as a RAF-MEK-ERK kinases downstream effector, we used two recently published gene expression data sets [25, 26] derived from metastatic CRC cell lines, “with primary resistance to cetuximab” querying for MEK inhibitor (MEKi) responsive genes (Fig. 4a). The gene discussed is MAP2K7; the disease is colorectal carcinoma.