ETH-Zurich researchers have discovered a new, surprising link between chloracne and a molecule that protects cells against stress: if Nrf2 gets out of control, disfiguring cysts form on the skin.The images were seen all over the world and stuck in the minds of many: in the autumn of 2004, former President of the Ukraine, Viktor Yushchenko, was poisoned with a high dose of dioxin.