Tested in CAL-62 thyroid cancer and MDA-MB-231cells, 3d displayed the strongest time- and dose-dependentreduction of cell viability and clonogenicity at a single-digit micromolarlevel, along with cell death, in both normoxia and hypoxia conditions.Moreover, 3d downregulated not only hypoxia-induced factors,such as HIF-1α, EPAS-1, and CA-IX, but also epithelial–mesenchymaltransition master regulators and extracellular matrix components suchas SNAIL1, ZEB1, SLUG, COL1A2, MMP2, and MMP9, markedly hamperingMDA-MB-231 cell migration. This evidence concerns the gene EPAS1 and thyroid cancer.