MMP3 and rheumatoid arthritis: A search of the U. S. National Library of Medicine database (MEDLINE) (http://www.ncbi.nlm.nih.gov/IEB/Research/Acembly/av.cgi) for genetic information focusing on the relationship between genetic variation and disease reported that matrix metalloproteinase-3 gene (MMP-3) and the tissue inhibitors of matrix metalloproteinases-3 gene (TIMP3) associated with rheumatoid arthritis and arthritis.