MMP9 and acute respiratory distress syndrome: Because rescue of aquaporin 5 (AQP-5) and matrix metalloproteinase 9 (MMP-9) and inhibition of apoptosis may lead to NF-κB attenuation [41], we speculate that NF-κB may be a key mediator of apoptosis, AQP-5/MMP-9, and PKC/SSeCKS/F-actin signaling pathways during AP-induced ALI.