The hemoglobin subunit epsilon 1 (HBE1) antibody is a tool used to detect the ε-globin protein, a component of embryonic hemoglobin (HbE, α2ε2). HBE1 is expressed during early fetal development (4–8 weeks gestation) and is gradually replaced by fetal hemoglobin (HbF, α2γ2) and later adult hemoglobin (HbA, α2β2). Research on HBE1 focuses on hemoglobin switching mechanisms, genetic blood disorders, and reactivation strategies for therapeutic purposes. For instance, elevated ε-globin expression is explored in treating β-hemoglobinopathies like sickle cell disease and β-thalassemia. The antibody is utilized in techniques such as Western blotting, immunohistochemistry, and flow cytometry to study ε-globin expression patterns in developmental biology models, hematopoietic stem cells, or gene-editing experiments (e.g., CRISPR-Cas9). Commercial HBE1 antibodies are typically validated for specificity against recombinant or endogenous ε-globin, with cross-reactivity checks against γ- or β-globin isoforms. Challenges include low endogenous HBE1 expression in postnatal samples, requiring sensitive detection methods. Its applications span basic research on globin gene regulation, clinical studies of hemoglobin disorders, and drug development targeting globin switching.