An artistically modified overlay of two fluorescence microscopic pictures of the baker’s yeast Saccharomyces cerevisiae, a prime example for a unicellular model organism. The yeast vacuoles were visualized in green (via a GFP-tagged vacuolar protein) as well as in blue (using a vacuolar lumen-specific dye). Pictures by Sabrina Büttner (University of Graz, Austria). The cover is published under the Creative Commons Attribution-NonCommercial-NonDerivative 3.0 license.