Histology and immunohistology of lung from WT, 4L, and 9 V/null mice. Lung sections were from 28-wk age-matched mice. Representative H&E sections showed no storage cells in the alveolar spaces of WT or 4L lungs, whereas abundant large storage cells were present in 9 V/null lung (e.g., arrows). Immunohistochemistry staining with CD68 and F4/80 antibodies showed large positively-staining storage cells in 9 V/null lung (e.g., arrows), i.e., macrophage origin. In comparison, 4L lung had a few, small CD68 and F4/80 positive cells (e.g., arrows). WT lungs did not exhibit positive-staining cells. The scale bars are 20 μm. Magnification = 400×.