HIF1A and Familial prostate cancer: In addition and consistent with this, HIF2A expression was below detection levels in all prostate cancer cell lines tested under normoxia and only detected in PC3s and DU145s under hypoxic conditions (Supplementary Fig S5G), thus validating the absence of ARRB1/HIF2A interaction and explaining the lack of compensation following HIF1A knock-down in our system.