Human gene for pancreas protein 2 (PAN2) is a novel member of the short-chain dehydrogenase/reductase gene superfamily. The properties of PAN2 protein have not yet been characterized. We present the first evidence that human PAN2 is a ubiquitously expressed microsomal enzyme that recognizes retinoids but not steroids as substrates with the apparent Km values between 0.08 μM and 0.4 μM. PAN2 is ∼4-fold more effecient in the reductive than in oxidative direction. The apparent Km values for NADP+ and NADPH are 0.65 μM and 0.32 μM versus 1200 μM and 1060 μM for NAD+ and NADH, respectively. Kinetic constants and expression pattern of PAN2 suggest that it is likely to function as a reductase in vivo and might contribute to the reduction of retinaldehyde to retinol in most human tissues. © 2002 Published by Elsevier Science B.V. on behalf of the Federation of European Biochemical Societies.