Neutrophil infiltration and activation in various organs of BERK mice. Neutrophils (brown staining) are present in the lungs and livers, but not kidneys, of BERK mice. Tissue levels of MPO were determined in the organs of WT (n = 8 or 9) and BERK (n = 10-12) mice. Asterisks directly above the bars indicate statistically significant difference compared with WT group: *P < .05.