Many studies have shown that some nutritional regulation strategies can reduce the expression of TLR-4 in RECs; for example, Jiang et al. [93] reported that the addition of quercetin to LPS-treated RECs exerted an anti-inflammatory effect by reducing TLR-4 expression, which fully proved the inflammatory pathway mechanism of RECs caused by HCD. The gene discussed is TLR4; the disease is heavy chain disease.