Claim: MMP10 is also involved in the breakdown of extracellular matrix in normal physiological processes and is secreted as inactive proproteins which are activated when cleaved by extracellular  proteoglycans.
Evidence: Proteins of the matrix metalloproteinase (MMP) family are involved in the breakdown of extracellular matrix in normal physiological processes, such as embryonic development, reproduction, and tissue remodeling, as well as in disease processes, such as arthritis and metastasis. Most MMP's are secreted as inactive proproteins which are activated when cleaved by extracellular proteinases.