Hemoglobin is a protein that is transported in red blood cells. It transports oxygen from the lungs into the peripheral tissues and into the cells. Alpha and beta are the two proteins that make hemoglobin. Both of these proteins have to be present in order for the hemoglobin to release and pick up oxygen properly. There are normal hemoglobin types, and variant hemoglobin types. The normal hemoglobin types that exist in your body are Hb A, Hb A2, and Hb F. Hb A makes up about 95 - 98 percent of Hb that is in your body (it consists of two alpha protein chains and two beta protein chains). Hba2 makes up about 2 percent of Hb in your body, containing two alpha and two delta protein chains. Lastly, Hb F is also about two percent of the Hb in your body, containing two alpha and two gamma protein chains. A variant hemoglobin type occurs when there are genetic changes in globin genes. Hemoglobin S, in people with sickle cell disease, is the primary hemoglobin. Hb S causes sickle cell shaped, deformed red blood cells because of less amounts of oxygen. Hemoglobin can be referred to as the oxygen transport protein.