Then, a massive increase of local and circulating pro-inflammatory cytokines, such as IL-6, is accompanied by elevated lung and circulating levels of humoral innate immunity pattern recognition molecules, including C-reactive protein (CRP), mannose-binding lectin (MBL), long pentraxin PTX3, and complement (Table 3) [65,66,67], whose activation further contributes to lung inflammation and damage in ARDS. Here, MBL2 is linked to acute respiratory distress syndrome.