Furthermore, HIF1A was upregulated (3.2-fold, P = 4.5 × 10–19) in MS patient CNS-infiltrating CD8+ T cells relative to controls, suggesting that this factor may act as an upstream regulator of the oxidative and nonoxidative arms of the PPP in response to RET-ROS signaling, as others have suggested (36, 37). This evidence concerns the gene HIF1A and myeloid sarcoma.