Of note, chemopreventive efficacy for aspirin was seen in CRCs from LS patients that almost uniformly carry WT copies of BRAF (23), whereas activating mutations in the BRAFV600E oncogene, detected in up to 15% of CRCs, are enriched in sporadic CRCs with defective MMR and microsatellite instability (MSI) due to epigenetic inactivation of MLH1 MMR gene