Intratumoral hypoxia Respiratory hyperoxia (60% O2) (9, 293) ➣ Breast: 4T1 (293) ➣ Melanoma: B16 (9) B16-F10 (293) CL8-1 (9) ➣ Fibrosarcoma: MCA205 (9, 293) ➣ Primary tumor expansion rate ↓ (9) ➣ Metastasis formation ↓ (293) CD4 > CD8 > NK cells (293) Host A2AR (293) Independent of 60%O2-induced ROS production (293) ➣ Survival ↑ (9, 293) ↓ Hypoxia (9, 293)↓ HIF- 1α (9)↑ FHL-1, FIH-1, VHL (HIF- 1α inhibitors) (9)↓ CD39, CD73, A2AR, A2BR, COX-2 mRNA (9)↓ extracellular adenosine (9)↑ CD8+, CD69+, CD44+ cells (293)↓ Tregs (293)↑ IL-2, IL-12, CXCL9, CXCL10, CXCL11 mRNA (293)↓ TGF-β (293)↓ FOXP3 in Tregs (293)↓ CD39, CD73, CTLA-4 on Tregs (293)↑ MHC class I on tumor cells (9)↓ VEGF, VEGF mRNA (9)↓ Microvessel density (9)