{"type":"root","children":[{"type":"paragraph","children":[{"type":"text","value":"Glycophorins A (GPA) and B (GPB) are single pass membrane sialoglycoproteins. GPA is the carrier of blood group M and N specificities, while GPB accounts for S and U specificities. GPA and GPB provide the cells with a large mucin-like surface and it has been suggested this provides a barrier to cell fusion, thus minimizing aggregation between red blood cells in the circulation. Anti-Glycophorin A has been used to characterize erythroid cell development."}]}]}