Like other solid tumors, as sarcomas outgrow their blood supply, hypoxia stabilizes HIF1α and HIF2α, which bind to HIF-β (ARNT), and drive the transcription of over 150 genes crucial in many aspects of cancer biology including angiogenesis, epithelial-mesenchymal transition, stem-cell maintenance, invasion, metastasis, and resistance to radiation therapy and chemotherapy [11] (Figure 1). Here, EPAS1 is linked to cancer.