NRAS and adenoma: The aim of the present study was to address this issue in a more systematic fashion, by analyzing the mutation spectrum of 14 well-known cancer genes (i.e. BRAF, NRAS, KRAS, PIK3CA, PIK3R1, EGFR, PTEN, MAP2K4, SMAD4, FBXW7 (CDC4), CTNNB1 (β-catenin), STK11, PDGFRA and APC) [18] in a large well-defined series of flat and polypoid adenomas using a high-throughput genotyping technique.