In addition, all of these significantly elevated factors were positively correlated with the symptoms of nasal obstruction in AR, which may be due to the stimulation of HDM to the monocyte-macrophage in the nasal mucosa to produce G-CSF, IFN-γ and TNF-ɑ, and increased secretion of IL-4, IL-6 by upregulating B lymphocytes, mast cells and basophils, and induced VCAM-1 on vascular endothelium, thus directing inflammatory cells to migrate to the site of inflammation and causing exacerbation of nasal symptoms (48, 49). This evidence concerns the gene TNF and Nasal congestion.