ENTPD1 and Zinc deficiency: The quantification of each adenine nucleotide and adenosine hydrolyzed from ATP revealed that the effects of zinc deficiency varied depending on the cell type, which can be attributed to the distinct expression pattern and level of ENTPD1/CD39, ENPP1, ENPP3, NT5E/CD73, TNAP, PAP, and their isozymes (see Fig. 3).