| Ap4A | diadenosine tetraphosphate |
| CD | cluster of differentiation |
| CE | capillary electrophoresis |
| CHES | N-cyclohexyl-2-aminoethanesulfonic acid |
| CD39 | nucleoside triphosphate diphosphohydrolase-1 |
| CD73 | ecto-5′-nucleotidase |
| DAD | diode array detector |
| DMEM | Dulbecco’s Modified Eagle Medium |
| EDTA | ethylenediaminetetraacetic acid |
| EHNA | erythro-9-(2-hydroxy-3-nonyl)-adenine |
| HEPES | 4-(2-hydroxyethyl)piperazine-1-ethanesulfonic acid |
| NTPDase1 | nucleoside triphosphate diphosphohydrolase-1 |
| NPP1 | nucleotide pyrophosphatase/phosphodiesterase-1 (CD203a) |
| pIC50 | negative log of the half-maximal inhibitory concentration |
| PBS | phosphate-buffered saline |
| pNP-TMP | p-nitrophenyl thymidine 5-monophosphate |
| PSB | Pharmaceutical Sciences Bonn |
| SDS | sodium dodecylsulfate |