SLC5A1 encodes SGLT1 (sodium-glucose cotransporter 1), an electrogenic Na(+)-coupled sugar symporter that actively transports D-glucose and D-galactose across cell membranes with a 2:1 Na(+) to sugar coupling ratio 1. SGLT1 plays critical roles in glucose homeostasis by mediating dietary glucose absorption in the intestine and glucose reabsorption in kidney proximal tubules, where it works complementarily with SGLT2 23. The transporter functions as both a glucose transporter and water channel, enabling passive water transport in response to osmotic gradients created during sugar uptake 1. Mutations in SLC5A1 cause glucose/galactose malabsorption, a genetic disorder affecting intestinal sugar absorption 2. Beyond metabolic transport, SGLT1 demonstrates therapeutic relevance as genetic studies suggest its inhibition may protect against cerebral small vessel disease and reduce frailty/sarcopenia through various metabolic mediators 45. Additionally, SLC5A1 expression has been implicated in glioblastoma cell migration, where the transporter localizes to the leading edges of migrating cells 6. These findings establish SGLT1 as a multifunctional transporter with roles spanning glucose homeostasis, water transport, and potential therapeutic applications in neurological and oncological contexts.