Effect of Tmprss6 haploinsufficiency on spleen size, serum EPO levels, and iron-related parameters of thalassemic mice. In the figure are graphed: spleen weights normalized to body weight (A), serum EPO levels (B), splenic (C) and hepatic (D) non-heme iron content (SIC and LIC), liver mRNA expression of Hepcidin normalized on LIC (Hamp/LIC; E), Bmp6 (F), inhibitor of DNA binding 1 (Id1; G), and Tmprss6 (H). mRNA expression ratio was normalized to a male WT mean value of 1. Mean values of 4 to 8 animals for sex and genotype (WT, Tmprss6^+/−, Hbb^th3/+ [th3/+], and Tmprss6^+/−Hbb^th3/+ [Tmprss6^+/−th3/+]) are graphed and error bars indicate SD. Asterisks refer to a statistically significant difference (*P < .05; **P < .01; ***P < .005). For complete statistical analysis see supplemental Table 3.