EPAS1 and neoplasm: To determine the role played by the HIF pathway in polyclonal CD8+ T cells during tumor growth, we subcutaneously grafted LLC and B16-F10 melanoma cells into mice specifically lacking HIF-1α or HIF-2α in T lymphocytes (HIF-1αfl/fldlckCRE or HIF-2αfl/fldlckCRE), and compared tumor growth with that seen in wild-type (WT) control littermates (HIF-1αfl/fl and HIF-2αfl/fl).