Meanwhile, if we compare the MSI frequency in various cancer types to the incidence of the MMR mutations we can see that the mutation rate of MMR genes in endometrial, gastric, colorectal, or ovarian cancers is significantly higher than the incidence of MSI determined by NGS, which is interesting since MMR genes can be turned off not only by mutations but also by methylation, which would result in a higher MSI rate than MMR gene mutation (Table 5). This evidence concerns the gene MRC1 and ovarian cancer.