SLC52A3 encodes a plasma membrane transporter mediating cellular uptake of riboflavin (vitamin B2), an essential water-soluble vitamin critical for oxidation-reduction reactions in carbohydrate, lipid, and amino acid metabolism 1. Since humans cannot synthesize riboflavin endogenously, intestinal absorption via SLC52A3 is essential 1. The SLC52A3 promoter is regulated by Sp1 transcription factor binding in intestinal epithelial cells 2. Loss-of-function SLC52A3 mutations cause autosomal recessive Brown-Vialetto-Van Laere syndrome (BVVLS) and Fazio-Londe disease (FLD), characterized by pontobulbar palsy, progressive muscle weakness, and respiratory insufficiency 34. Early riboflavin supplementation significantly improves neurological outcomes in affected patients, though sensorineural hearing loss may persist 4. Slc52a3 knockout mice exhibit neonatal lethality with severe riboflavin deficiency, hyperlipidemia, and hypoglycemia, demonstrating SLC52A3's critical role in placental riboflavin transport 5. Beyond monogenic disorders, genome-wide association studies identified SLC52A3 as a novel Alzheimer's disease susceptibility locus in Chinese populations 6. The rs13042395 polymorphism is associated with reduced cancer risk and favorable prognosis in esophageal squamous cell carcinoma, with the TT genotype predicting lower lymph node metastasis and longer relapse-free survival 78.