MLH1 and colorectal cancer: Additionally, we examined the expression of DNA mismatch repair enzymes, hMLH1 and hMSH2 protein, in epithelial and stromal cells, respectively, as the MSI-H phenotype has been suggested to be of importance for the DNA mismatch repair system in sporadic colorectal cancers (Dietmaier et al, 1997; Ward et al, 2001).