The article Electrically tunable liquid crystal optical microresonators was recently published in Nature Photonics (Nature Photonics 3, 595 - 600 (2009)) by Matjaž Humar, Miha Ravnik, Stane Pajk and Igor Muševič from the Faculty of Mathematics and Physics and the "Jožef Stefan" Institute, appearing also on the front cover of the issue. The authors demonstrate electrically tunable, low-loss whispering-gallery-mode (WGM) resonators made of nematic liquid crystal droplets, embedded in a polymer matrix. The shift in resonant frequencies is achieved via electric field-induced structural distortion of the birefringent liquid crystal resonator medium. Nematic liquid crystal microresonators have a large tuning range of the order of 20 nm for a 600 nm WGM and high Q-factors up to 12,000. The tunability is approximately two orders of magnitude larger than usually achieved in solid-state microresonators.