SLC2A3 encodes GLUT3 (glucose transporter 3), a facilitative glucose transporter that mediates cellular uptake of glucose and other monosaccharides including galactose, mannose, xylose, and fucose, but not fructose 12. Beyond its canonical glucose transport function, SLC2A3 exhibits glucose transport-independent roles in cellular signaling and endocytosis. In macrophages, GLUT3 localizes primarily to endosomes and is essential for M2 polarization through direct interaction with GTP-bound RAS, facilitating IL-4Rα endocytosis and STAT6 activation 3. The protein shows tissue-specific expression patterns, being predominantly neuronal but also expressed in immune cells, heart, and cancer tissues 4. Disease relevance includes roles in atopic dermatitis and wound healing, where GLUT3 promotes M2 macrophage function 3, and in rheumatoid arthritis as a ferroptosis-related biomarker 5. SLC2A3 copy number variants at chromosome 12.31 are associated with various neuropsychiatric, cardiovascular, and immune diseases, particularly affecting cellular states with increased energetic demands such as organ development and proliferation 4. The gene also plays roles in skin fibrosis through mechano-metabolic pathways and spermiogenesis through substrate protection mechanisms 67.