TIMP metallopeptidase inhibitor 1, a member of the TIMP family. The glycoprotein is a natural inhibitor of the matrix metalloproteinases (MMPs), a group of peptidases involved in degradation of the extracellular matrix. In addition to its inhibitory role against most of the known MMPs, the encoded protein is able to promote cell proliferation in a wide range of cell types, and may also have an anti-apoptotic function.Transcription of TIMP-1 is highly inducible in response to many cytokines and hormones. In addition, the expression from some but not all inactive X chromosomes suggests that TIMP-1 inactivation is polymorphic in human females. TIMP-1 is located within intron 6 of the synapsin I gene and is transcribed in the opposite direction.