Independent of any conclusions regarding our evaluation of ALI vs. control subjects, two technical observations regarding our assessments of the lung biopsies using EPX-mAb immunohistochemistry relative to H&E staining are noteworthy: (i) EPX-mAb immunohistochemistry is an easily performed assessment that provided a >40fold enhancement to detect tissue infiltrating eosinophils. This increased sensitivity not only allowed for the greater detection of tissue infiltrating eosinophils but also corresponding increases in the speed, accuracy, and reproducibility of this determination. (ii) EPX-mAb immunohistochemistry provided a rapid and definitively quantitative assessment of eosinophil degranulation within the lung parenchyma, observable even in the absence of intact infiltrating eosinophils.