In total, 30 (61%) of 49 neoplasms with MSI-High status by PCR had a somatic null mutation of an MMR gene or methylation of the MLH1 gene promoter, whereas only 5 (0.78%) of 634 neoplasms with MSS patterns had a somatic null MMR gene mutation or MLH1 methylation (p < 0.001) (Table 4). The gene discussed is MRC1; the disease is neoplasm.