Cover picture: Embryonic day 13 piece of mouse cochlear epithelium cultured for 5 d in vitro and immunostained with myosin VI, a hair cell marker (red), and DAPI, a nuclear marker (blue). Hair cells developed in the absence of mesenchyme and formed a small group of differentiated cells. For details, see the article by Montcouquiol and Kelley in this issue (pages 9469–9478).