EGFR and colorectal cancer: However, one should keep in mind that in vitro assessment may not reproduce in vivo behavior; for example, despite all the models showing activation of the Mitogen-Activated Protein Kinase (MAPK) pathway by BRAF p.V600E mutations, colorectal cancers with this mutation are not sensitive to vemurafenib, because of the activation of a feedback loop leading to Epidermal Growth Factor Receptor (EGFR) activation [73].