Tmprss6 deficiency modifies systemic iron homeostasis in 4-week-old Hfe^−/− mice. (A-C) Effect of Tmprss6 genotype on serum and tissue iron parameters of 4-week-old female Hfe^−/− mice. Graphed are mean values obtained from analyses of TS (A), LIC (B), and spleen nonheme iron concentration (C) in 8 Hfe^−/−Tmprss6^+/+, 8 Hfe^−/−Tmprss6^+/−, and 6 Hfe^−/−Tmprss6^−/− mice. (D-G) Effect of Tmprss6 genotype on hepatic mRNA expression of genes involved in Bmp/Smad signaling in 4-week-old female Hfe^−/− mice. Graphed is the mean mRNA expression of Bmp6 (D), hepcidin (Hamp; E), Smad7 (F), and Id1 (G) relative to β-actin (Actb) in 6 mice per genotype. Error bars represent SD. NS indicates not significant.