Myeloid cell hepcidin expression in a subcutaneous model of infection. (A) Immunohistochemistry using anti-mouse hepcidin and anti-polymorphonuclear leukocyte (PMN) antibodies on skin of WT and Tlr4^Lps-d mice challenged with group A Streptococcus (GAS); controls include omission of primary antibody and addition of blocking peptide to the hepcidin antibody. (B) Immunohistochemistry using anti-mouse hepcidin antibodies on bone marrow of mice challenged with GAS; control corresponds to the addition of hepcidin blocking peptide to the hepcidin antibody. Magnification, × 400.