Seems to act as a signaling molecule involved in the maintenance of iron homeostasis. Seems to be required in conjunction with HFE to regulate both intestinal iron absorption and iron storage in macrophages. Has strong antimicrobial activity against E.coli ML35P N.cinerea and weaker against S.epidermidis, S.aureus and group b streptococcus bacteria. Active against the fungus C.albicans. No activity against P.aeruginosa.