In the breast cancer cell lines MCF-7 and T-57D, shRNA targeting HIF-2α suggested that HIF-2α drives hypoxia-induced WNT1 inducible signaling pathway protein 2 (WISP2) expression as it was significantly reduced when HIF-2α was depleted [53], but this effect was not observed in other breast tumor cell lines such as BT-474 and ZR-75–1, suggesting a lack of functional conservation even in similar cancer cell types. This evidence concerns the gene CCN5 and breast carcinoma.