Immunoblot analysis of extracellular matrix (ECM) proteins in lungs of Eln+/+ and Eln+/− neonatal mice, showing increased abundance of collagen-1 (A) and lysyl oxidase proteins in Eln+/− (B) pups; similar amounts of fibrillin-1 protein in Eln+/+ and Eln+/− pups (C); and less fibrillin-2 protein in Eln+/− pups (D), compared with Eln+/+ pups. Summary data; means and SD; *significant difference, P < 0.05. E: immunohistochemical localization of collagen-1 (arrows, brown stain) in lung sections of Eln+/+ and Eln+/− pups, showing prominent collagen-1 around microvessels, especially notable in the Eln+/− lung (panel on right and inset). Lungs: ×400 magnification; insets: ×680 magnification; scale bar = 50 μm.