Hepcidin induction and effects on serum iron during acute Influenza virus A/PR/8/34 infection of mice. qRT-PCR measurement of (A) Hepcidin (Hamp1), (C) Id1 and (D) Fibrinogen α chain (Fga) mRNA expression relative to the endogenous control gene Hprt1 in the livers of 6-week-old female C57BL/6 mice terminated 3 days after intranasal infection with 3.5 HAU Influenza A virus (A/PR/8/34) (n = 7 mice) or mock-infected (PBS; n = 8 mice). Serum was taken at termination for calculation of (B) transferrin saturation. **P < .01, ***P < .001, t test. (E) Pearson correlation between hepcidin and Fga mRNA levels in livers of infected mice.