Vegfa protein analysis. A. Immunohistochemistry for Vegfa on lung sections of normoxic and hyperoxic mice at three time points (D5, D28, and D56). Brown staining indicates Vegfa (marked with arrows) and blue staining (Mayer’s hematoxylin counterstain) indicates nuclei. Vegfa-positive cells associated with blood vessels are marked with arrows. Blood vessels are marked with “v”. Scale bar = 50 μm. B. Western blot for Vegfa (21 kDa). Actb is used as the loading control (42 kDa). Norm – Normoxia, Hyp – Hyperoxia.