No need to be a chemist or an avocado fan to enjoy any of these educational, scientific chemical molecule gifts featuring persin. Caption says it all: "Fungicidal Toxin Present In Avocado". Persin is generally harmless to humans, but when consumed by domestic animals in large quantities it is dangerous. This toxin has been suggested as a treatment for breast cancer. Make others do a double-take with chemistry attitude today with any of these persin molecule gifts!