Enables hemoglobin binding activity and identical protein binding activity. Involved in several processes, including response to X-ray; response to growth hormone; and response to vitamin. Located in Golgi apparatus; blood microparticle; and endoplasmic reticulum. Used to study obesity and type 1 diabetes mellitus. Biomarker of several diseases, including artery disease (multiple); diabetes mellitus (multiple); hepatocellular adenoma; kidney failure (multiple); and middle cerebral artery infarction. Human ortholog(s) of this gene implicated in Plasmodium falciparum malaria; artery disease (multiple); gout; hemolytic anemia; and hyperglycemia. Orthologous to several human genes including HP (haptoglobin). [provided by Alliance of Genome Resources, Apr 2022]