This gene encodes a key enzyme of the nonoxidative pentose phosphate pathway that provides ribose-5-phosphate for nucleic acid synthesis and nicotinamide adenine dinucleotide phosphate (NADPH) for lipid biosynthesis. The encoded protein is important for maintaining structure and function of mitochondria. Studies in knockout mice identify that deficiency of this gene product is a cause of sperm dysmotility and male infertility. Deficiency of this protein has also been identified as a cause of hepatocarcinogenesis in mice. Two related pseudogenes have been identified on chromosome 10. [provided by RefSeq, Mar 2010]