Expression of IFNg and pro-inflammatory cytokines in lung macrophages of WT, 4L, and 9 V/null mice. Lung sections were from 28-wk age-matched mice. Large storage cells in 9 V/null lungs were positive for IFNg, IL-6, and NOS2 (arrows). In 4L lung, a few, small NOS2 signal positive cells present (arrows). WT lungs did not exhibit positive staining. The scale bars are 20 μm. Magnification = 400×.