SLC25A14 (also known as UCP5/BMCP1) is a mitochondrial inner membrane carrier protein that functions as a multisubstrate transporter. Its primary role is transporting inorganic anions including sulfate, sulfite, thiosulfate, and phosphate, with particularly high affinity for sulfate and thiosulfate 1. The protein also mediates transport of dicarboxylates (malonate, malate, citramalate) and tricarboxylates, as well as aspartate and glutamate, though with lower efficiency 1. SLC25A14 catalyzes both rapid counter-exchange and very low uniport of substrates 1. Beyond anion transport, SLC25A14 exhibits proton transmembrane transporter activity and lesser chloride transport capacity, helping maintain oxidative balance through uncoupling activities and modulating mitochondrial membrane potential 23. A proposed physiological role is exporting hydrogen sulfide degradation products (sulfite and thiosulfate) from mitochondria, thereby modulating H2S signaling levels 1. SLC25A14 expression increases during prefrontal cortex development and correlates with fear-related behaviors in mice 4. While initial genetic studies did not identify SLC25A14 mutations in X-linked congenital nystagmus families 5, somatic variants in SLC25A14 have been identified in head and neck paragangliomas 6. SLC25A14 has been identified as a hub gene potentially contributing to Alzheimer's disease pathogenesis through tricarboxylic acid cycle pathway involvement 7.