MLH1 and colorectal cancer: Interestingly, it was reported that monoallelic MYH, one of BER genes, germline mutations showed a negative correlation with MSI in colorectal cancer patients.22 It was also reported that BER deficiency was rarely accompanied by CIN (Chromosomal instability) or MSI.23 Another study showed that MLH1 −93G>A polymorphism was associated with an increased risk of MSI-H colorectal cancer.24 Thus, we investigated whether MSI might be associated with hOGG1 Ser326Cys polymorphism in colorectal cancers and found no significant result.