NT5E and Hepatic fibrosis: Increased levels of adenine nucleotides in the extracellular space give rise to adenosine in models of both dermal and hepatic fibrosis as a result of nucleoside triphosphate dephosphorylase (CD39)- and ecto 5′-nucleotidase (CD73)-mediated dephosphorylation of adenine nucleotides (Peng et al., 2008; Fernandez et al., 2013).