4-Aminobenzoyl-Gly-Pro-D-Leu-D-Ala hydroxamic acid, also called MMP Inhibitor I, is a broad spectrum inhibitor of MMP-1 and MMP-8 (collgenases, IC50=1.0μM), MMP-9 (granulocyte gelatinase, IC50=50μM), and MMP-3 (skin fibroblast stromelysin, IC50=50μM).