Firstly, we have not investigated the effect of passive demethylation via decitabine on distant enhancers or the many alternate promoters of ESR1. Secondly, the results from breast tumour biopsies could have been confounded by the presence of 5’hydroxymethylation, which is present in primary tissue but not in in vitro cultured cell lines (and high passage number cell lines in particular). This evidence concerns the gene ESR1 and breast neoplasm.