This pathway can also be aberrantly activated by mutations in the K-RAS gene, a mutation carried by almost 50% of patients with CRC [88] and by HCT-116 et DLD-1 cell lines (K-RAS G13D) (Table 1), but this mutation cannot alone explain the level of intrinsic radio-sensitivity in our cell lines. This evidence concerns the gene KRAS and colorectal carcinoma.