HIF1A and neoplasm: In contrast, if tumor tissue is locally hypoxic, as implied in the HIF-1α immunohistochemical staining for MC-38 [10] and H460 grafts, with many regions of HIF-1α-positive cells (Supplementary Materials Figure S2), and where hemoglobin is not fully oxygen-saturated before hyperoxic challenge, T1 is expected to be unaffected.