Epitope-tagged Fpn is functional. HEK293T cells were transiently transfected using the Amaxa nucleofector with empty vectors or vectors containing mouse Fpn with the designated carboxyl terminal epitopes, or zebrafish Fpn with an amino terminal FLAG. After 24 hours, cells were cultured with FAC (10 μM iron) for 24 hours and ferritin levels determined by ELISA. Error bars represent the standard deviation of 3 separate experiments in duplicate.