EGFR and metastatic colorectal cancer: Molecular genetic studies targeting metastatic colorectal cancer (mCRC) tumors have identified mutations in KRAS and NRAS that predict a lack of therapeutic response to epidermal growth factor receptor (EGFR) inhibitors (Bokemeyer et al. 2015; Douillard et al. 2013; Peeters et al. 2013; Van Cutsem et al. 2015).