MMP9 and Duchenne muscular dystrophy: We evaluated the expression, activation, and immunolocalization of MMP-2 and MMP-9, as well as of regulatory molecules MT1-MMP, TIMP-1, TIMP-2 and RECK, in the dystrophin-deficient skeletal muscle of the canine X-linked muscular dystrophy in Japan (CXMDJ) model of DMD, which shows more prominent skeletal muscle involvement than mdx mice [39].