DECR2 is a 292 amino acid member of the short-chain dehydrogenases/reductases (SDR) protein family and the 2,4-dienoyl-CoA reductase protein subfamily. Localized to the peroxisome, DECR2 is an auxiliary enzyme of beta-oxidation that catalyzes the NADP-dependent reduction of 2,4-dienoyl-CoA to yield trans-3-enoyl-CoA. DECR2 has also been shown to have catalytic activity towards 2,4,7,10,13,16,19-docosaheptaenoyl-CoA and short and medium chain 2,4-dienoyl-CoAs, suggesting that DECR2 is not a rate limiting step in the degradation of docosahexaenoic acid in the peroxisome. DECR2 is expressed as three isoforms produced by alternative splicing events.