Last week, Science Daily reported on a German Cancer Research Center study (Nature, 2015) to note that, “Environmental stress is a major factor in driving DNA damage in adult hematopoietic stem cells, researchers have found, concluding that a good night’s sleep keeps your stem cells ‘young.'” The attached photo shows healthy bone marrow packed with blood cells (left) and (right) the bone marrow of stressed mice showing the depletion of blood cells and replacement with fat cells. The Science Daily report is here: