Tumor necrosis factor-alpha (TNF) is a pleiotropic cytokine. which is thought to play a major role in the pathogenesis of inflammatory diseases. including allergy. TNF is produced at the early stage of allergen sensitization. https://www.bekindtopets.com/flash-grab-Viqua-F4-Ultraviolet-Water-System-Powered-by-UVMax-36-gpm-top-savings/