Matriptase-2, a membrane protein encoded by the Tmprss6 gene, is a negative regulator of hepcidin expression. Although matriptase-2 has been proposed to cleave membrane hemojuvelin, we have recently found decreased hemojuvelin protein levels in Tmprss6 -/- mice. The purpose of this study was to confirm this observation by determining hemojuvelin protein levels in another strain of mice with dis...