BRCA1 and squamous cell carcinoma: In several other tumor-associated genes, such as BRCA1 in ovarian cancer22 and CDKN2A in squamous carcinoma,23 the causal relevance of epigenetic changes has been supported by the finding that such silencing events are mutually exclusive with mutational inactivation of the same gene.24 To analyze if DNA hypermethylation at DMR2 is related to genomic mutations of DNMT3A, we sequenced the exons 18, 19 and 23 in our AML samples.