Expression of IL-4, MMP12 and Arg2 in lung macrophages from WT, 4L, and 9 V/null mice. Lung sections were as in Figure 2, 9, 10 and 11. Large storage cells in 9 V/null lungs were positive for IL-4, MMP12, and Arg2 (e.g., arrows), whereas only a few were in 4L lungs. WT lungs were negative. The scale bars are 20 μm. Magnification = 400×.