Band 3

Band 3 anion transport protein, also known as anion exchanger 1 (AE1) or band 3 or solute carrier family 4 member 1 (SLC4A1), is a protein that is encoded by the SLC4A1 gene in humans.

Band 3 anion transport protein is a phylogenetically-preserved transport protein responsible for mediating the exchange of chloride (Cl) with bicarbonate (HCO₃) across plasma membranes. Functionally similar members of the AE clade are AE2 and AE3.