MMP2 and Arthritis: Sixteen days after arthritis induction 57–60 kDa MMP isoform, 75 kDa MMP-2 and 92 kDa MMP-9, but at 30 days only 57–60 kDa isoform increased significantly in the ankle joint homogenates of both arthritic groups as compared to the non-arthritic controls (Figure 3A–I).