Pluripotent stem cells hold great promise for future applications in many areas of regenerative
medicine. Their defining property of differentiation towards any of the three germ layers and all derivatives
thereof, including somatic stem cells, explains the special interest of the biomedical community in this cell type.
In this review, we focus on the current state of directed differentiation of pluripotent stem cells towards
hematopoietic stem cells (HSCs). HSCs are especially interesting because they are the longest known and,
thus, most intensively investigated somatic stem cells. They were the first stem cells successfully used for
regenerative purposes in clinical human medicine, namely in bone marrow transplantation, and also the first
stem cells to be genetically altered for the first successful gene therapy trial in humans. However, because of
the technical difficulties associated with this rare type of cell, such as the current incapability of prospective
isolation, in vitro expansion and gene repair by homologous recombination, there is great interest in using
pluripotent stem cells, such as Embryonic Stem (ES-) cells, as a source for generating and genetically altering
HSCs, ex vivo. This has been hampered by ethical concerns associated with the use of human ES-cells.
However, since Shinya Yamanaka´s successful attempts to reprogram somatic cells of mice and men to an
ES-cell like state, so-called induced pluripotent stem (iPS) cells, this field of research has experienced a huge
boost. In this brief review, we will reflect on the status quo of directed hematopoietic differentiation of human
and mouse pluripotent stem cells.