KRAS and colorectal carcinoma: A comparison of the clinicopathological and tumor molecular features showed that patients with MSI tumors were older, as has been previously observed in sporadic CRC [34,35]; MSI tumors were associated with poor differentiation by histology, BRAF mutations and right-sided location, whereas MSS tumors displayed a higher frequency of KRAS mutations; this is in line with observations in other studies [36,37].