Mutations in RAS proto-oncogenes (comprising H-, N- and K-RAS) are among the most common in malignant tumours and although RAS isoforms are very similar, KRAS is more frequently found mutated in cancers occurring in 22% of all tumours analysed compared to 8% for NRAS and 3% for HRAS[7]. The gene discussed is KRAS; the disease is neoplasm.