ERFE enhances hemoglobin synthesis in a dose-dependent manner. Hemoglobin levels (A-B), red blood cell (RBC) counts (C-D), and mean corpuscular hemoglobin (MCH) levels (E-F) at 6 (A,C,E) and 16 (B,D,F) weeks of age in male (M, square) and female (F, circle) WT (white symbols) and Erfe-overexpressing (TG, colored symbols) mice from line-L (white/pink), line-M (white/red), and line-H (white/dark red). Group means are indicated by blue lines, and groups within each individual line and age group were compared by using 2-way analysis of variance to determine significant effects of genotype (Gt) and sex on data variation and to identify interactions (Int) between these variables (P < .05 denoted in bold red). In the event of significant Int between Gt and sex, individual groups were compared by using Šidák’s multiple comparisons test. P ≥ .05, not significant (ns).