This gene encodes a member of the xanthine dehydrogenase protein family. The encoded protein has been identified as a moonlighting protein based on its ability to perform mechanistically distinct functions. The encoded protein exists as two distinct enzymatic forms, either as xanthine dehydrogenase, or as xanthine oxidase, and functions in purine degradation. Additional studies also suggest a role in adipogenesis, and a function as a structural protein in milk fat droplets in the lactating mammary gland. [provided by RefSeq, Jan 2014]