Nevertheless, genomic mutation of DNA mismatch repair genes has rarely been documented in sporadic gastric carcinoma with MSI-High (MSI-H) [10], and several early papers reported that hypermethylation of the CpG island in the MutL homolog 1 (MLH1) promoter DNA presents with a loss of MLH1 protein expression in almost all cases of MSI-H sporadic gastric carcinomas [10, 12–14]. This evidence concerns the gene MLH1 and gastric carcinoma.