Another example regarding the correlation between HIF-1 and EZH2 has been revealed in a study conducted some years ago in which the expression of EZH2 in breast tumor initiating cells (BTICs) is enhanced by hypoxia through HIF1α-mediated transactivation, which promotes the expansion of BTICs and cancer progression (78, 79). The gene discussed is HIF1A; the disease is breast neoplasm.