Mediates the hydrolysis of some nucleoside diphosphate derivatives. Can degrade 8-oxo-dGTP in vitro, suggesting that it may remove an oxidatively damaged form of guanine (7,8-dihydro-8-oxoguanine) from DNA and the nucleotide pool, thereby preventing misincorporation of 8-oxo-dGTP into DNA thus preventing A:T to C:G transversions. Its substrate specificity in vivo however remains unclear (By similarity). May have a role in DNA synthesis and cell cycle progression throught the interaction with PCNA.Synonyms: 7, 8-dihydro-8-oxoguanine-triphosphatase NUDT15, MTH2, MutT homolog 2, Nucleoside diphosphate-linked moiety X motif 15, Nudix motif 15, Probable 8-oxo-dGTP diphosphatase NUDT15