BIRC5 and breast carcinoma: Proteins expressions of β-catenin, survivin and axin2 were significantly increased, and p-β-catenin expression was decreased in HIF-2α overexpressing MCF7 and MDA-MB-231 cells compared to the NC group (Fig. 3a), suggesting that HIF-2α overexpression could activate the Wnt pathway in breast cancer cells.