These outcomes are likely mediated by the down-regulation in levels of expression of the DNA methyltransferases, especially DNMT1. For the GBM0.2 tumours, DNA demethylation was further enhanced by the up-regulation of TET1, which mediates the transition from 5mC to 5hmC [52], resulting in these tumours being most hypo-methylated. The gene discussed is TET1; the disease is neoplasm.