EPAS1 and breast cancer: Intriguingly, the anti-clonogenic effect was the most remarkable.Moreover, since reduced SIRT3 expression in human breast cancer hasbeen reported to lead to HIF-1α stabilization and upregulationof HIF-1α target genes, we explored the effects of compounds 3a–d in modulation of HIF-1α, EPAS-1 (HIF-2α)and CA-IX expression in both CAL-62 and MDA-MB-231 cells after 48h of treatment.