Treatment success using Cetuximab and Panitumumab for treatment of metastatic colorectal cancer depends on a nonmutated KRAS gene; the treatment is ineffective if the KRAS gene has any mutations [1, 5, 6, 8], which leads to an activated G-protein even in absence of the ligand, like the epidermal growth factor [9, 10]. This evidence concerns the gene KRAS and metastatic colorectal cancer.