Cover legend: Light microscope image of a Drosophila eye stained with toluidine blue. Tangential section of the compound eye reveals regularly spaced ommatidia with seven darkly stained rhabdomeres in each. The Drosophila homolog of a human Niemann-Pick disease gene (dnpca1) is required for survival of photoreceptors and other neurons. For more information, see the article by Phillips et al. in this issue (pages 6569–6582).