Nucleoside diphosphate kinase A, a member of the NDK family, is also known as NME1, NDP kinase A (NDPA), granzyme A-activated DNase (GAAD), metastasis inhibition factor nm23 (NM23-H1) and tumor metastatic process-associated protein. NME1 plays a major role in the synthesis of nucleoside triphosphates other than ATP. NME1 is also involved in cell proliferation, differentiation and development, signal transduction, G protein-coupled receptor endocytosis, and gene expression. Furthermore, NME1 is required for neural development including neural patterning and cell fate determination. During GZMA-mediated cell death, NME1 works in concert with TREX1. NME1 nicks one strand of DNA and TREX1 removes bases from the free 3' end to enhance DNA damage and prevent DNA end reannealing and rapid repair.