Membrane type 1 matrix metalloproteinase (MT1-MMP; MMP-14) is a zinc-dependent type I transmembrane endopeptidase with very important roles both in physiological (epithelial morphogenesis, skeletal development, and wound healing) and pathological (angiogenesis, arthritis, tumor growth, and metastasis, obesity, inflammation, and atherosclerosis) events. The gene discussed is MMP14; the disease is arthritic joint disease.