There is little evidence for a relationship between H3K9Ac levels and non-CpG methylation, especially in breast cancer cells, but in this study, we noted that H3K9ac level inversely correlate to methylated cytosine content, namely, lower level of H3K9ac is found in the non-CpG/CpG region around the TSS of HIF-1α promote in MCF-7 cells, and higher level are found in MDA-MB-231 cells. The gene discussed is HIF1A; the disease is breast cancer.