TLR4 and polycystic ovary syndrome: Later, Wang et al. found that quercetin reduced the levels of the inflammatory cytokines IL-1β, IL-6, and TNF-α by regulating the oxidized low-density lipoprotein (OX-LDL)/Toll-like receptor 4 (TLR-4)/nuclear factor κB (NF-κB) pathway, improving the inflammatory microenvironment of ovarian tissue and reversing IR in dehydroepiandrosterone (DHEA)-induced PCOS rats (Wang et al., 2017).