CXCR4 and ovarian carcinoma: In the TME, PGE2 can mediate T‐cell inhibition indirectly through multiple pathways.52, 67 In the ovarian cancer ascites, PGE2 can induce the secretion of CXCL12 and the expression of CXCR4 to promote MDSC accumulation, which inhibits T‐cell functions.5 Hypoxia, a characteristic of ovarian cancer TME, can upregulate the expression of COX‐2 and subsequently promote the synthesis of PGE2.31