Glut1 is highly expressed on erythrocytes of all mammalian species during the neonatal period. (A) Surface Glut1 expression was assessed on neonatal and adult human RBCs obtained from umbilical cord and peripheral blood samples, respectively, using an eGFP-tagged HTLV receptor-binding domain (H_RBD) fusion protein¹⁷  that specifically binds this transporter.¹⁶  (B) Glut1 expression was monitored on murine, rat, bovine, and canine erythrocytes at the indicated day of life. Control stainings are presented as shaded histograms.