Cover photograph (Copyright © 2013, American Society for Microbiology. All Rights Reserved.): High-magnification transmission electron micrographs of Candida albicans cell walls after growth on lactate (blue [left]) or glucose (red [right]) reveal the impact of the carbon source on cell wall architecture (magnification, ×36,000). The outer fibrillar layer is made up of mannoproteins, while the inner layer is composed of chitin and β-glucan polymers. These cell wall components are pathogen-associated molecular patterns, recognized by the human innate immune system. Samples were imaged with a Philips CM10 transmission microscope (FEI, United Kingdom) equipped with a Gatan 600W camera, and images were recorded using DigitalMicrograph software (Gatan, Abingdon Oxon, United Kingdom). (See related article on p. 238.)