Unexpectedly, similar to the well‐known hypoxia‐inducible protein, hypoxia‐inducible factor 1α (HIF1α), hypoxia could induce the expression of OVOL2 protein in MCF7, ZR75‐1 and MDA‐MB‐231 breast cancer cells (Figure 6A and Figure S7A, Supporting Information), suggesting that OVOL2 expression is regulated at the protein level. This evidence concerns the gene HIF1A and breast cancer.