By clarifying the structural biology of CD45 among hematopoietic cells, our data further indicate that multiple E-selectin-binding CD45E isoglycoforms can exist (e.g., CD45RABC-E, CD45RBC-E, and CD45RB-E) but are each exclusively restricted to immature hematopoietic cells (i.e., CD34+ HSPCs and AML blasts). This evidence concerns the gene CD34 and acute myeloid leukemia.