Matrix metalloproteinase-21 (MMP-21) is an enzyme that in humans is encoded by the MMP21 gene.

This gene encodes a member of the matrix metalloproteinase family. Proteins in this family are involved in the breakdown of extracellular matrix for both normal physiological processes, such as embryonic development, reproduction, and tissue remodeling,and disease processes, such as asthma and metastasis. The encoded protein may play an important role in embryogenesis, particularly in neuronal cells, as well as in lymphocyte development and survival. [provided by RefSeq, Jul 2008]. Publication Note: This RefSeq record includes a subset of the publications that are available for this gene. Please see the Gene record to access additional publications.
Function: May have an important and specific function in tumor progression and embryogenesis. Cleaves alpha-1-antitrypsin.