MLH1 and Lynch syndrome: A molecular analysis study of 63 SBA tumors showed MMR deficiency (dMMR) in 14 tumors with confirmed Lynch syndrome in 9 of 14 cases, suggesting that the higher frequency of dMMR seen in SBA as compared to CRC may be explained by a higher frequency of Lynch syndrome in SBA patients, and that the etiology for MSI-high appears to be more commonly related to Lynch syndrome in SBA as opposed to MLH-1 promoter hypermethylation in CRCs [32].