TLR4 and endometriosis: In animal experiments, investigators injected lipopolysaccharide (LPS) into the peritoneum of mouse model of endometriosis and found that the activation of LPS/TLR4 pathway induced the expression of nuclear factor-κB (NF-κB) and promoted its translocation to the nucleus, causing peritoneal macrophages and ectopic endometrial cells to release inflammatory factors (68).