Fig. 3
Systemic levels of biomarker in ARDS patients stratified by age group. Systemic levels of a interleukin (IL)-6, b IL-8, c IL-10, d Fractalkine, e intracellular adhesion molecule (ICAM)-1, f angiopoetin 2:angiopoetin 1 (ANG2:ANG1), g platelet factor (PF) 4, h tissue plasminogen activator (tPA), i protein C, at onset of ARDS. 
Young adults, 
middle-aged adults, and 
elderly. Box and whisker diagrams depict the median and lower quartile, upper quartile, and their respective 1.5 IQR as whiskers—as specified by Tukey. Group differences between young adults and middle-aged adults, and young adults and elderly were tested by a Mann-Whitney U test. A p value < 0.05 was considered as statistical significant