The aryl hydrocarbon receptor (AHR) is a cytosolic ligand-activated transcription factor involved in xenobiotic sensing, cell cycle regulation and cell development. Aryl hydrocarbon receptor (AHR) is a chemical sensor that is expressed abundantly in epidermal keratinocytes. Oxidative AHR ligands induce the production of reactive oxygen species. However, antioxidant AHR ligands inhibit reactive oxygen species generation via activation of nuclear factor-erythroid 2-related factor-2, which is a master switch for antioxidative signalling. In addition, AHR signalling accelerates epidermal terminal differentiation, but excessive acceleration by oxidative ligands, such as dioxins, may induce chloracne and inflammation. However, antioxidative phytochemical ligands induce the beneficial acceleration of epidermal differentiation that repairs skin barrier disruption. Aryl hydrocarbon receptor (AHR) is a ligand activated transcription factor and involved in tumorigenesis of many cancers. To sum-up we found that AHR signalling pathway components were upregulated, as the grade of the meningioma progresses from low to high grade, suggesting an important role of AHR signalling pathway in human meningioma. Aryl hydrocarbon receptor (AHR) is a ligand-activated transcription factor, connecting environmental stimulators with the immune system. AHR had been demonstrated an anti-inflammatory role in macrophages, which suggest that decreased AHR expression is associated with pro-inflammatory M1 macrophage and BD susceptibility.