MTHFR and thymoma: The methylation-sensitive high-resolution melting technique for the analysis of DNA methylation levels of genes involved in one-carbon metabolism and DNA methylation in blood, tumor tissue, and healthy thymic epithelial cells from thymomatous MG patients showed significantly higher methylation of the methylenetetrahydrofolate reductase (MTHFR) promoter in thymomas, as well as some degrees of methylation of the DNMT3A gene in thymic tissue with respect to blood [55].