mRNA levels of various MMPs and TIMPs in cartilage layers derived from inflamed knee joints. Cartilage layers were isolated from patellae and tibia, three and seven days after IFN-γ accelerated arthritis. The cycle threshold value (Ct) of the various MMP and TIMP genes was corrected for glyceraldehyde-3-phosphate dehydrogenase content and t = 0. Note that at day 3, MMP-12 and at day 7 MMP-3 mRNA levels were significantly elevated in p47phox-/- mice when compared to controls (6A and B). TIMP mRNA levels were not altered (6C and D).