SLC25A40 is a mitochondrial transporter that mediates glutathione (GSH) import from the cytosol into mitochondria 1. As the primary function, SLC25A40 facilitates the translocation of GSH across the inner mitochondrial membrane, a critical process since GSH is synthesized exclusively in the cytosol but required within mitochondria 1. Mechanistically, SLC25A40 operates as a solute carrier family member, localizing to mitochondrial membranes and regulating redox homeostasis 2. Mitochondrial GSH is essential for maintaining iron-sulfur cluster stability in electron transport chain proteins and supporting erythropoiesis 13. In disease contexts, SLC25A40 dysregulation contributes to multiple pathologies. Elevated SLC25A40 expression in doxorubicin-resistant leukemia cells promotes drug resistance and proliferation by enhancing mitochondrial GSH 4. In non-small cell lung cancer, SLC25A40 upregulation drives tumor growth by increasing NADPH-mediated lipid synthesis and suppressing ferroptosis 5. Conversely, rare missense variants in SLC25A40 are associated with hypertriglyceridemia, implicating the transporter in lipid metabolism 6. Clinically, SLC25A40 represents a potential therapeutic target in cancer and metabolic disorders, and its mutations may contribute to epilepsy susceptibility 2.