Adding the EGFr-targeted drug panitumumab to chemotherapy augments progression-free survival (PFS) in first- [11] and second-line [12] settings and is superior alone over the best supportive care for patients with metastatic colorectal cancer who have progressed on oxaliplatin- and irinotecan-containing regimens [13]. This evidence concerns the gene EGFR and metastatic colorectal cancer.