The hematopoietic stem cell (HSC) is an undifferentiated, pluripotent cell, which will give rise to all the fundamental cells of the blood: red blood cells, white blood cells and platelets.
It is a cell that retains the ability to proliferate and multiply. In other terms it is capable to replicate itself and, simultaneously, generate new cells that, through processes of differentiation and development, will originate mature cellular elements.
It is for this reason that HSC maintain their function throughout all life time.
If we think that the daily turnover and the need of new cells is 10¹¹-10¹² (100.000.000.000-1.000.000.000.000) it is easy to understand the proliferative potential of HSC.