Background/Objectives: Hypoxia promotes esophageal adenocarcinoma (EAC) aggressiveness through stabilization of hypoxia-inducible factor-1α (HIF-1α), which regulates pro-survival, pro-metastatic, and immunosuppressive pathways, including the ectoenzyme CD73 (NT5E). The gene discussed is NT5E; the disease is esophageal adenocarcinoma.