Sequencing the Events That Mediate Progression of Premalignant Lung Lesions. 
Analysis of a large group of patients with multifocal premalignant disease by Krysan and colleagues in this issue of Cancer Research provides an informative view of the processes that may underlie progression of these lesions to invasive adenocarcinoma of the lung.  The identification of the type and distribution of mutational changes reveals that common processes may be occurring within individuals but that these are generally unique between patients at risk for developing lung cancer.  Furthermore, predicted neoantigens are identified and associated with characteristics of immune infiltrates supporting the role of alterations in adaptive immune surveillance in progression of these premalignant lesions.  These findings provide critical insights that will help establish a foundation of knowledge for developing personalized prevention strategies with the potential to significantly impact overall mortality in lung cancer. See related article by Krysan et al.,  p. 5022.