To further investigate the physiological function of FPN1 (encoded by Slc40a1) in controlling iron homeostasis during viral infection, Slc40a1fl/fl mice were crossed with Lyz2cre mice to specifically knockout FPN1 in myeloid cells (referred to as “FPN1CKO”) (Fig. S2j, k). The gene discussed is SLC40A1; the disease is viral infectious disease.