Integrins are heterodimeric cell surface receptors composed of alpha and beta subunits，which mediate cell-cell and cell-extracellular matrix attachments. They are responsible for adhesion of platelets and other cells to collagens，modulation of collagen and collagenase gene expression，force generation and organization of newly synthesized extracellular matrix. Aberrant integrin expression has been found in many epithelial tumours. Changes in integrin expression have been shown to be important for the growth and early metastatic capacity of melanoma cells.