Hemoglobin subunit epsilon is a protein that in humans is encoded by the HBE1 gene.

The epsilon globin gene (HBE) is normally expressed in the embryonic yolk sac: two epsilon chains together with two zeta chains (an alpha-like globin) constitute the embryonic hemoglobin Hb Gower I; two epsilon chains together with two alpha chains form the embryonic Hb Gower II. Both of these embryonic hemoglobins are normally supplanted by fetal, and later, adult hemoglobin. The five beta-like globin genes are found within a 45 kb cluster on chromosome 11 in the following order: 5' - epsilon – gamma-G – gamma-A – delta – beta - 3'.

This article incorporates text from the United States National Library of Medicine, which is in the public domain.