Hemoglobin Subunit Delta A type of polypeptide chain that when in combination with alpha globin polypeptide chains forms adult hemoglobin 2 (HbA2). HbA2 comprises around 3% of adult hemoglobin. Hemoglobin subunit delta (147 aa, ~16 kDa) is encoded by the human HBD gene. This protein plays a role in the transport of oxygen to tissues of the adult body. Hemoglobin Delta Chain Sufficient Haemoglobin Subunit Delta SCDO:1000011 Haemoglobin Delta Chain NCIT:C84980 Delta-Globin Delta Globin https://www.ncbi.nlm.nih.gov/gene/3045 http://bioportal.bioontology.org/ontologies/NCIT?p=classes&conceptid=http%3A%2F%2Fncicb.nci.nih.gov%2Fxml%2Fowl%2FEVS%2FThesaurus.owl%23C84980 Beta-Globin Family Members