Changes

<span style="font-size:20px;">Stem cell aging: mechanisms, regulators and therapeutic opportunities: </span>[https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4160113/https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4160113/]<br/> <br/> <br/> '''Exit from dormancy provokes DNA-damage-induced attrition in haematopoietic stem cells&nbsp;'''[https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4160113/ '''https://www.nature.com/articles/nature14131''']