The gene C17orf25 was isolated from the liver by RACE PCR. nudt9 gene was screened by yeast two-hybrid method in MatchMaker human HeLa cDNA library. NUDT9 is an enzyme that has pyrophosphatase activity with ADP-ribose as its substrate. Fusion expression of C17orf25 and GFP and computer analysis showed that C17orf25 was probably located in mitochondria. Furthermore, C17orf25 may suppress the cell growth by interaction with NUDT9.