Chronic inflammation in PCOS, involving interleukin (IL)-6, IL-16, IL-18, tumour necrosis factor (TNF) -α, and C-reactive protein (CRP), may play a role in the endometrial oxidative stress imbalance as well as the upregulated expression of intercellular adhesion molecule 1, TNF-α, and metalloproteases. The gene discussed is TNF; the disease is polycystic ovary syndrome.