Lack of vitamin A in the body has a detrimental effect on the hematopoietic system in the bone marrow. The deficiency causes a loss of important blood stem cells, scientists from the German Cancer Research Center (DKFZ) and the Heidelberg Institute of Stem Cell Research and Experimental Medicine (HI-STEM) now report in the latest issue of the journal Cell. These findings will open up new prospects in cancer therapy.