In total, 30 (57%) of 53 neoplasms with dMMR had a somatic null mutation of an MMR gene or methylation of the promoter of the MLH1 gene, whereas only 7 (1.1%) of 653 with normal/indeterminate dMMR IHC patterns had a somatic null MMR gene mutations or MLH1 methylation (p < 0.001) (Table 4) (Case-level data can be seen in the Supplementary Text for Results and Supplementary Table S1). The gene discussed is MRC1; the disease is neoplasm.