Functional roles of transferrin in the brain

► Oligodendrocytes and choroid plexus express Tf mRNA in the brain. ► Choroid plexus secretes Tf, while Tf in oligodendrocytes is reportedly not secreted. ► Tf delivers iron to neurons but glial cells do not have mechanisms for Tf uptake. ► The amount of Tf that enters the brain through the BBB may be minimal. ► Tf in the CSF may serve as a biomarker for some neurological diseases.