On the cover: Left panel: 3-D reconstruction of MRI images showing the heart and large vessels of a Hey1/L deficient mouse embryo (stage E15.5). The ventricular myocardium was digitally removed to allow a view at the heart chambers. There is an open connection between both ventricles (ventricular septal defect) denoted by a double-headed arrow. See pp. 856–863. Right panel: Vegf120/120 mouse embryonic heart of E12.5 shows remarkable developmental abnormalities. The most obvious are hypoplasia of the pulmonary trunk (green) and a ring of subpulmonary apoptotic myocardium (purple). The aortic arch is shown in pink and the cardiac cushions in yellow. See pp. 842–849.