Hemopexin (or haemopexin) is a plasma protein that binds heme with the highest affinity of any known protein. Hemopexin is generally expressed in liver, and belongs to acute phase reactants, the synthesis of which is induced after inflammation. Heme is potentially very toxic because of its ability to intercalate into lipid membrane and to generate hydroxyl radicals. Hemopexin's function of scavenging the heme released or lost by the turnover of heme proteins such as hemoglobin defends the body from the oxidative damage that free heme can cause. Additionally, hemopexin discharges its bound ligand for internalisation upon interacting with a specific receptor located on the surface of liver cells. This hemopexin function is in order to preserve the body's iron. Hemopexin's levels in the serum are an indication of how much heme is present in the blood. Low Hemopexin levels show that there is a lot of it in the serum. For that reason, low hemopexin levels indicate that there has been considerable degradation of heme containing compounds - mainly hemoglobin, it indicates hemolysis and low hemopexin levels are therefore one of the diagnostic features of a hemolytic anemia. It's a Haem binding protein used in the assessment of intravascular haemolysis in conjunction with haptoglobin. Hemopexin, Beta-1B-glycoprotein, HPX, Haemopexin