Characteristics of BAL cells. Following BAL the cells were removed by centrifugation and counted. Total cell numbers (A) were determined from an aliquot of cell suspension applied to a hemocytometer. Differential cell counts (B) were obtained by making cytocentrifuge preparations of BAL cells and doing differential cell counts. Gray bars represent FA-exposed samples and black bars represent ozone-exposed samples. Note that FA-exposed values are plotted in B, but values are very small (0.125% and 0% for WT and KO, respectively). Comparisons that were significantly different are indicated by a bracket and p-values.