Cover image: Pictured is an electron micrograph of the alveolar structure in a mouse model of lung disease. Chronic obstructive pulmonary disease (COPD), which includes lung diseases such as emphysema, affects 10% of the human population worldwide and has been difficult to recapitulate in mice. Florie Borel et al. used CRISPR/Cas9-mediated genome editing to generate a mouse model of COPD. The mice spontaneously developed emphysema and exhibited many of the disease phenotypes observed in human COPD. According to the authors, the mouse model might aid the preclinical development of therapeutics for COPD. See the article by Borel et al. on pages 2788–2793. Image courtesy of Florie Borel and Lara Strittmatter (University of Massachusetts Medical School, Worcester, MA).