MIA is the first discovered member of a family of secreted cytokines termed the MIA/OTOR family. The four known members of this family; MIA, MIA2, OTOR and TANGO each contain a Src homology-3 (SH3)-like domain. MIA is an autocrine growth regulatory protein secreted from chondrocytes and malignant melanoma cells that promotes melanoma metastasis by binding competitively to fibronectin and laminin in a manner that results in melanoma cell detachment from the extracellular matrix in vivo. Elevated levels of MIA may represent a clinically useful marker for diagnosis of melanoma metastasis as well as a potential marker for rheumatoid arthritis. Recombinant human MIA is a 12.2 kDa globular protein containing 108 amino acid residues including two intramolecular disulfide bonds. .