In another word, although HIF-1alpha is primary regulated at the post-translational levels, there is transcriptional regulation of HIF-1alpha in breast cancer cells, such as the methylation at CpG and non-CpG dinucleotides in the HIF-1α promoter around the TSS which is mainly mediated by DNMT3a.. The gene discussed is DNMT3A; the disease is breast cancer.