Expression of TNFα and colocalization with CD68 in lung macrophages from WT, 4L, and 9 V/null mice. Anti-CD68 is green (FITC) and anti-TNFα is red (Alexa-610). Abundant large storage cells in 9 V/null lungs were CD68 or TNFα positive (e.g., arrows). 4L and WT lungs showed a few scattered small positive cells but none appeared to be positive for both antibodies. TNFα and CD68 colocalized in many of 9 V/null macrophages (yellow). The scale bars are 20 μm. Magnification = 400×.