Common TAS2R38 taste receptor gene variants specify the ability to taste phenylthiocarbamide (PTC). 6-n-propylthiouracil (PROP) and structurally related compounds. Tobacco smoke contains a complex mixture of chemical substances of varying structure and functionality. some of which activate different taste receptors. https://www.bekindtopets.com/quick-grab-Canine-Spectra-KC-3-Single-Dose-great-price/