EPO and anemia: The aforementioned experiments using Fpn1Tek/Tek and Fpn1Alb/Alb;LysM/LysM mice suggest that factors other than liver iron levels regulate the expression of Bmp6. Because Tf-bound iron [23], anemia, Epo, and erythropoietic activity [5], [33]–[34] are all factors that influence Hamp1 expression, we hypothesized that some or all of these factors might be involved in regulating Bmp6 expression in our mouse models.