Fig 1: CD39 and CD73 leading to elevated levels of extracellular adenosine.

Extracellular adenosine 5′-triphosphate (ATP) is released by dying and damaged cells, and it acts on many immune cells to promote inflammation. On the other hand, the unphosphorylated
metabolite, adenosine, functions as an anti-inflammatory molecule. Two extracellular ecto-5´-Nucleotidases, CD39, and CD73, convert extracellular ATP to ADP/AMP and AMP to adenosine, respectively, leading to elevated levels of extracellular adenosine (Fig 1).