Since patients do not have metastatic disease, response rates for both arms should be even higher – probably in the region of 90 % since in the EXPERT C study XELOX and XELOX and cetuximab provided clinical response rates of 64 and 54 % respectively overall, and 71 % versus 51 % for patients expressing wild type KRAS [49]. This evidence concerns the gene KRAS and metastatic neoplasm.