Although not predictive of outcome with standard chemotherapy, KRas mutation status is a strong predictive marker of resistance to EGFR-targeted therapy in patients with metastatic colorectal cancer (i.e., KRas mutations predict a lack of response to anti-EGFR monoclonal antibodies cetuximab and panitumumab) [34–39]; this topic is discussed in detail in another paper in this series, “Impact of KRas mutations on management of colorectal cancer” by Sullivan and Kozuch. Here, KRAS is linked to colorectal cancer.