On the cover: Subcutaneous bleomycin elicits fibrosis and endothelial-to-mesenchymal transition in the lung of Cdh5-CreER^T2::R26R-EYFP transgenic mice. Representative immunofluorescence staining using Abs specific for CD31 (endothelium; violet), α-SMA (myofibroblasts; red), and EYFP⁺ (endothelial-derived cells; green) on lung section of PBS- or of bleomycin-treated Cdh5-CreER^T2::R26R-EYFP mice. Nuclei are counterstained with DAPI (blue). Nicolosi, P. A., E. Tombetti, A. Giovenzana, E. Donè, E. Pulcinelli, R. Meneveri, M. Tirone, N. Maugeri, P. Rovere-Querini, A. A. Manfredi, and S. Brunelli. 2019. Macrophages guard endothelial lineage by hindering endothelial-to-mesenchymal transition: implications for the pathogenesis of systemic sclerosis. J. Immunol. 203: 247–258.