The hematopoietic (blood-forming) stem cells (HSCs) residing in our bone marrow produce all of our blood cells, including key immune cells that protect us from bacteria and viruses. As we age, our HSCs become less efficient and less able to make healthy new blood cells. In a study published online today in Nature, researchers at Albert Einstein College of Medicine have found that this reduction in HSC efficiency is caused in part by the deterioration of chaperone-mediated autophagy (CMA), the housekeeping process that removes damaged proteins and other waste materials that interfere with cells’ ability to function.