TLR4 and polycystic ovary syndrome: Additionally, Shen et al. discovered that BBR might alleviate PCOS by inhibiting apoptosis and regulating the expression levels of toll-like receptor 4 (TLR4), tyrosine kinase (LYN), PI3K, Akt, NF-κB, TNF-α, IL-1, IL-6, and caspase-3, which contributed to the improvement of IR (Shen et al., 2021a).