HFE, but not HFE-C282Y and HFE-H63D, increases ALK3 cell-surface expression. Hep3B cells were transfected with ALK3-Flag in the presence or absence of HFE-HA (WT), HFE-HA (C282Y), and HFE-HA (H63D). Forty-eight hours after transfection, whole cells were incubated with and without Sulfo-NHS-LC-LC-Biotin, and the cell lysates were precipitated with Streptavidin Agarose. The whole-cell lysates and avidin precipitates were subjected to western blot analysis with antibodies as indicated. A nonspecific membrane protein was used as loading control. The experiment was repeated 3 times.