HIF1A and breast cancer: Although it was already demonstrated that nuclear β-arr1 interacts with the primary factor mediating the response to low oxygen tension HIF-1α in breast cancer cells, a first genome wide-map of β-arr1 transcriptome in prostate cancer cells reported binding sites for β-arr1, p300 and HIF-1α on the regulatory regions of HIF-1α target gene promoter under hypoxic or pseudohypoxic conditions [47, 48].