Here, we have investigated the interaction between human FPN (hsFPN) and its inhibitor vamifeport, which was shown to ameliorate anemia and iron homeostasis in a mouse model of β-thalassemia and is now in clinical development for this disorder and sickle cell disease (Manolova et al., 2019; Nyffenegger et al., 2022). Here, SLC40A1 is linked to sickle cell disease.