Stabilization of HIF-1α and its translocation to the nucleus induces target gene transcription and expression. To monitor the ability of compounds to promote HIF-1α transcriptional activity, a luciferase reporter assay was performed in HeLa (Figure ) and U2OS (Figure ) cells stably expressing an HRE-luciferase reporter. Treatment with compounds 1, 30 and 33 caused a concentration-dependent increase in HIF-dependent luciferase activity, while as expected no activity was observed for cisVH298. Inhibitors 30 and 33 proved to be more efficacious than benchmark compound 1, with compound 30 even matching the HREdependent luciferase activity of the highly potent PHD inhibitor daprodustat at 150 µM.