The clone AD2, a mouse monoclonal antibody recognizes a 70kD glycophosphatidylinositol (GPI)-linked 5'nucleotidase (or 5'-Ecto-nucleotidase) cell surface antigen known as CD73. It is widely expressed on various immune as well as non-immune cells including T and B cells, mesenchymal stem cells, follicular dendritic cells, endothelial cells, epithelial cells, etc. CD73 catalyzes the conversion of extracellular nucleosides to adenosine and modulates immune responses. Administration of CD73 inhibits metastasis formation in human breast cancer by inducing clustering and internalization of CD73 expressed on the surface of cancer cells.