Pages L415–L424: Cui H, Ge J, Xie N, Banerjee S, Zhou Y, Liu R, Thannickal VJ, Liu G. miR-34a promotes fibrosis in aged lungs by inducing alveolar epithelial dysfunctions. Am J Physiol Lung Cell Mol Physiol 312: L415–L424, 2017. First published December 15, 2016; doi:10.1152/ajplung.00335.2016.—H. Cui and J. Ge contributed equally to this study. The article has been corrected online.