AbstractThe addition of butyric acid to murine erythroleukemic cells (clone T3C12) induced the cells to differentiate, producing adult hemoglobin (A, α2,β2) and an embryonic hemoglobin (E2, α2Y2). The subsequent addition of hemin to the differentiating cells increased the synthesis of adult hemoglobin four‐fold and the synthesis of embryonic hemoglobin two‐fold; the relative synthesis of the α and β globins increased more than the Y globin. The embyronic hemoglobin was expressed prior to the adult hemoglobin in differentiati