SLC35D2 is a Golgi-localized nucleotide sugar antiporter that transports UDP-N-acetylglucosamine (UDP-GlcNAc) and UDP-glucose (UDP-Glc) from the cytosol into the Golgi lumen in exchange for UMP 1. The protein contains 10 transmembrane helices and maps to chromosome 9.33 1. As a member of the SLC35 nucleotide sugar transporter family, SLC35D2 supplies activated sugar substrates to glycosyltransferases within the Golgi, supporting heparan sulfate proteoglycan biosynthesis 2. Recent crystal structure analysis of the yeast SLC35D2 homolog Vrg-4 has provided mechanistic insights into antiporter function and substrate recognition 2. Beyond normal glycosylation, SLC35D2 is co-opted by the intracellular pathogen Chlamydia trachomatis to import UDP-glucose into the parasitophorous vacuole, enabling bacterial glycogen synthesis and nutrient sequestration 3. In breast cancer cells, SLC35D2 expression is downregulated following disruption of chondroitin/dermatan sulfate biosynthesis, indicating coordinated regulation of glycosaminoglycan synthesis pathways 4. SLC35D2 mRNA is expressed ubiquitously across adult and fetal tissues 5. A genetic variant in SLC35D2 showed association with overall survival in advanced non-small cell lung cancer patients, suggesting potential clinical relevance 6.