Mutational analysis of KRAS and NRAS is already used routinely to determine suitability to receive anti-epidermal growth factor receptor (EGFR) therapy.2–5 Mutational status of BRAF is becoming widely recognised as a prognostic marker, with the presence of an activating mutation in stage IV being associated with very poor prognosis.2, 6–8 Mutational activation of PIK3CA9 or loss of pTEN protein expression10, 11 has been implicated in driving signalling through the AKT pathway, which is a feature in up to 30% of CRC. Here, NRAS is linked to colorectal carcinoma.