Farnesol, (2E,6E)- is an isoprenoid found in many aromatic plants and is also produced in humans, where it acts on numerous nuclear receptors and has received considerable attention due to its apparent anticancer properties. Farnesol is present in many essential oils such as citronella, neroli, cyclamen, lemon grass, tuberose, rose, musk, balsam, and tolu. It is used in perfumery to emphasize the odors of sweet floral perfumes. Its method of action for enhancing perfume scent is as a co-solvent that regulates the volatility of the odorants. It is especially used in lilac perfumes. Farnesol is a natural pesticide for mites and is a pheromone for several other insects. In a 1994 report released by five top cigarette companies, farnesol was listed as one of 599 additives to cigarettes. Farnesol has been suggested to function as a chemopreventative and anti-tumor agent. Farnesol is subject to restrictions on its use in perfumery as some people may become sensitized to it, however, the evidence that farnesol can cause an allergic reaction in humans is disputed.