About the cover: Cover is based on immunohistochemical analysis of a lung biopsy from a full-term newborn with unexplained respiratory distress syndrome. The analysis revealed a moderate (immunohistochemical score 2) ABCA3 protein expression in type-II pneumocytes in an infant with a heterozygote E66K SFTPC mutation. For more information, see article by Brasch and colleagues, beginning on page 571.