NE can activate Toll-like receptor 4 (TLR-4) and the TLR4-mediated mitogen-activated protein kinase (MAPK) signaling pathway and further activate NF-κB through the Myeloid Differentiation Factor 88 (MyD88)-dependent TLR-4 signaling pathway, promoting the release of inflammatory factors such as TNF-α and IL-6, leading to an inflammatory cascade that is involved in the pathogenesis of lung diseases [13,14]. The gene discussed is TLR4; the disease is lung disorder.