The severity of the disease was reflected by variations of BMP-15, glypican 3, IGFBP-4, IL-5, IL-22 BP, leptin, or orexin B between day 1 and day 7 of ARDS patients, while the representative of SP was defined by the differentiation from the healthy and ARDS patients (e.g., 6Ckine, CD14, IL-1 R4 /ST2, IGFBP-2, IGF-I, or BD-1), which may be useful for early diagnosis and monitoring for SP patients. Here, IL22 is linked to acute respiratory distress syndrome.