The function of ENSG00000078177 (N4BP2, NEDD4 binding protein 2) is as follows. Has 5'-polynucleotide kinase and nicking endonuclease activity. May play a role in DNA repair or recombination (PubMed:12730195). May play a role in the non-stop mRNA decay pathway (NSD), which specifically targets and degrades mRNAs that lack a proper stop codon (PubMed:40441874). {ECO:0000269|PubMed:12730195, ECO:0000269|PubMed:40441874}.