KRAS and neoplasm: Indeed, right-sided CRCs emerge proximal (right) to the splenic flexure in a very different milieu, compared with left-sided CRCs (distal), and are thought to progress through an alternative serrated neoplasia pathway, molecularly underpinned by mutations in BRAF or KRAS, microsatellite instability, and a CpG island methylator phenotype [239,240].