KRAS and adenoma: While the step-wise progression of premalignant lesions to carcinomas in the classical adenoma-carcinoma sequence is characterised by chromosomal instability (CIN) and APC or KRAS mutations, the molecular profiles described in serrated neoplasias include specific BRAF and KRAS mutations, microsatellite instability (MSI), and a CpG island methylator phenotype (CIMP) [8–11].