The cover images are photomicrographs (400X magnification; courtesy of Carmen Behrens, M.D., and Ignacio Wistuba, M.D.)of hematoxylin-eosin–stained sections of cell pellets obtained from cultured normal human bronchial epithelial cells (top)and increasingly transformed derivative cells (center and bottom). A model of this series of cells was used to derive gene-expression profiles (transcriptomes) of neoplastic progression. These molecular signatures were then applied to the Shedden dataset of resected lung adenocarcinoma patients, where the most informative signature correlated with outcome and did so without the addition of clinical factors. This is the first test of a premalignancy-derived molecular signature in a clinical dataset. See articles by Kadara et al. (beginning 702) and Carbone (beginning 695) for more information.