Hemangioblast is defined as a precursor cell with the potential to differentiate into both hematopoietic and endothelial cell lineages. The concept that the hemangioblast exists was first introduced more than 80 years ago, and it has since gained support from studies that the hematopoietic and endothelial lineages share expression of a number of genes, such as CD34, VEGF R2/Flk-1, SCL, CBFA2/RUNX1, and GATA-1.