Cover picture: An Amoeba proteus cell stained for microtubules (green) and F-actin (red). The fluorescence images are overlaid (bottom left). The bright-field image (bottom right) shows many endogeneous particles, whose displacements were tracked to study the viscoelasticity of the cytoplasm in the crawling cell, yielding information on the structure and dynamics of the cytoskeleton. See the article by Rogers et al. on page 3313.