EGFR and colorectal carcinoma: In contrast to melanoma cell lines, vemurafenib therapy failed to permanently sustain reduction of phospho-ERK (P-ERK) expression in CRC cell lines, and after just 24 h, higher expression of P-ERK was observed, mediated by the EGFR-mediated activation of RAS and CRAF, leading to reactivation of the MAPK pathway [68].