NCIt definition : A tetrameric complex of 2 molecules of hemoglobin subunit alpha (encoded by either
the HBA1 or HBA2 gene) and 2 molecules of hemoglobin subunit gamma (encoded by either
the HBG1 or HBG2 gene).;
NCIt note : Hemoglobin F is expressed by fetal red blood cells and its production drops soon after
birth and reaches levels found in adults within 1 to 2 years. In adults, hemoglobin
F accounts for less than 2% of the normal erythrocyte hemoglobin in adults.;