CD73, also known as NT5E, CD73 (ecto-5'-nucleotidase) is a novel immunoinhibitory protein that plays a key role in tumor growth and metastasis. CD73 is an important part of the adenosine signaling pathway.The expression of CD73 is higher in tumours than in the corresponding healthy tissues and associated with a poor prognosis. CD73, mainly by the production of adenosine, is critical in the suppression of an adequate anti-tumour immune response, but also in promoting cancer cell proliferation, tumour growth, angiogenesis, and metastasis.