SIRT1 and malignant colon neoplasm: In relation to specifically MSI and CIMP in CRC, two previous studies investigated SIRT1 expression and one found that SIRT1 overexpression was more common in tumour tissue samples of both MSI- and CIMP-high colon cancers than other MSI/CIMP subtypes44, while the other found that loss of SIRT1 expression was associated with MSI-high CRC45.