NT5E and cancer: CD73 (ecto-5′-nucleotidase anchored to glycosylphosphatidylinositol) is essential for the generation of extracellular adenosine from 5′-adenosine monophosphate (5′-AMP), being expressed by different cancer types, causing tumor growth, metastasis, and, in some cases, treatment resistance, by immune evasion of tumor cells, leading to adenosine accumulation, which interferes with NK cells’ cytotoxic ability [72].