Overall, 38% of patients had KRAS exon 2 mutations, and 10% had RAS mutations beyond KRAS exon 2 (KRAS exon 3 and 4 mutations each in 3% of tumours; NRAS exon 2 and 3 mutations each in 2% of tumours; no tumour was found to carry an NRAS exon 4 mutation). Here, NRAS is linked to neoplasm.