In case of intravascular or extravascular hemolysis or hemorrhage the deleterious effects of cell-free Hb are thought to be controlled mainly via the action of Hp [44], that binds to Hb with high affinity [18, 45] and promotes its clearance by monocytes and resident macrophages of the reticuloendothelial system via scavenger receptor CD163 [19]. The gene discussed is HP; the disease is hemorrhage.