CD8A and neoplasm: Overall, oxygen concentration during anesthesia in pFLASH groups had lower effect on the immune cell infiltration into tumor tissues, except for a greater number of infiltrating CD8 T cells in rats that received no supplemental oxygen during anesthesia (p-value of multiple comparisons pFLASH with O2vs pFLASH without O2p-value = 0.0151), CD8+ TRM T cells (p-value = 0.0038) and NK cells (p-value = 0.0440) (Fig. 4b).