Hematopoietic (stem) cells—The elixir of life?

The long lifespan of humans is often not matched with health span. Thus, there is a need for rejuvenation strategies. Here, we first discuss the evolutionary benefits of the long human lifespan, particularly when coupled with an extended health span. We then highlight the importance of understanding the complexity of aging before interfering with it. This raises the question of the optimal target for rejuvenation. We propose the blood system and hematopoietic stem cells (HSCs). Their decline is associated with dysfunction and disease in other organs, crystallizing them as a central player in organismal aging. We present rejuvenation strategies targeting the hematopoietic system, especially HSCs, and explore their systemic benefits. Overall, we summarize the potential of the blood system to reverse aging. Impact statement There is a current need to reduce the economic burden caused by aging-related diseases. In this perspective article, we discuss the evidence that supports that rejuvenating or delaying aging of the blood system has a beneficial and systemic impact on human health.