Evaluation of serial lung sections following EPX-mAb immunohistochemistry demonstrated that the density of pulmonary eosinophils in the collective group of ALI patients is significantly higher relative to control subjects (3.6-fold, 2.88 eosinophils/hpf vs. 0.81 eosinophils/ hpf (p < 0.01), respectively). More importantly, further evaluations of the ALI patients ( Figure 2 , shaded histograms) surprisingly showed that EPX-mAb detection of infiltrating lung eosinophils divided these patients into subjects which survived vs. those that did not survive hospitalization (8.4 ±2.9 eosinophils/hpf vs. 1.9 ± 0.6 eosinophils/hpf, p < 0.01).