CCL5 and neoplasm: The expression of chemokines such as Cxcl5, Ccl5, Cxcl1, and Cxcl3 present a peak at 3% oxygen for 48 h, which indicated that the immune function of macrophages may be involved in the recruitment of other immune cells in this hypoxic condition (51), while the major histocompatibility complex molecules such as H2-Q6, H2-Q9, and H2-Q10 present a successive increase in hypoxic condition, and the tumor immune microenvironment regulatory genes (Itgal, Tnfsf9, Ripor2, and Icos) showed a slight decrease at 1% oxygen for 24 h.