TWSG1 inhibits BMP2/4 up-regulation of hepcidin in primary human hepatocytes. Dose response of relative hepcidin expression levels to (A) BMP2 and (C) BMP4 are shown using primary hepatocytes from 4 separate donors (shaded bars). Final BMP concentrations are on the x-axis, and relative hepcidin expression on the y-axis (0 ng/mL assigned a value of 1 for comparison). In panels B and D, dosed response of relative hepcidin expression to TWSG1 in human primary hepatocytes cultured in 10 ng/mL BMP2 or BMP4, respectively. Lines represent results from 4 separate donors' cells from triplicate cultures. *P < .05.