In colorectal cancer, cetuximab, an IgG1 chimeric monoclonal antibody against EGFR, was associated with a significant improvement in overall survival (OS, hazard ratio [HR] for death, 0.77; 95% confidence interval [CI], 0.64 to 0.92; p = 0.005) and in progression-free survival (PFS, HR, 0.68; 95% CI, 0.57 to 0.80; p < 0.001) (Jonker et al., 2007). This evidence concerns the gene EGFR and colorectal cancer.