Yoo et al. reported that MTA1 induced the deacetylation and enhanced the stability of hypoxia-inducible factor-1α (HIF-1α) by recruiting HDAC1 in breast cancer cells, which indicates that a close connection may exist between MTA1-associated metastasis and HIF-1α-induced tumor angiogenesis [26]. This evidence concerns the gene HDAC1 and breast cancer.