Hypoxia favors neutrophil viability and function.322 Hypoxia recruits polymorphonuclear neutrophils (PMNs), which are the main effector cells against endometrial adenocarcinoma growth, and induces cancer cell detachment from the basement membrane.323 Upon relief of tumor hypoxia, recruitment of PMNs to the TME is significantly reduced; however, the recruited cells can efficiently kill cancer cells by releasing NADPH oxidase-associated MMP-9 and ROS.324. This evidence concerns the gene FMO5 and cancer.