Curr Opin Hematol 1996 Nov;3(6):473-9
The expression of blood group antigens was ubiquitously upregulated in the endothelial cells of fetal organs. In the process of their differentiation to endothelial naive embryonic mesenchymal cells expressed cytoplasmic ABH antigens. They were assumed as products of the activation of the respective genes. ABH antigen expression was considered as suggestive evidence for the assumption that blood group antigens could serve as early immunomorphologic markers of endothelial differentiation of mesenchymal cells, thus specifying the location of future blood vessels. Extending the conceptual framework of blood group antigens' significance we consider them as being possibly involved in the process of fetal morphogenesis.