MMP-9 expression in RAGE TG compared to controls. Lungs from control (Co, A) and RAGE TG (B) mice were qualitatively immunostained for MMP-9 and blinded counts of MMP-9 positive (+) cells were averaged per high powered field (HPF, C). Images were at 100X original magnification. Immunoblotting for MMP-9 using standardized aliquots of 10 μg total lung protein revealed markedly increased MMP-9 expression in RAGE TG mouse lungs compared to controls (D). *Statistical difference (P ≤ 0.05) with at least three replicates per group.