Hematopoietic Stem Cells (HSCs) maintain the life-long production of blood cells, as they reside atop of the hematopoietic tree. HSCs are quiescent and retain the highest self-renewal capacity, and have evolved mechanisms to respond to stresses, such as infections or blood loss. As chemotherapeutic treatment targets hematopoetic progenitors and cycling cells, HSCs have to exit quiescence to replenish the hematopoietic system. The sustained effects of chemotherapy on HSC functionality remain unclear. My PhD project aims to investigate the hematopoietic regeneration incuded by serial chemotherapeutic treatment, and how these repetitive challenges contribute to the establishment of an epigenetic memory on HSCs, and aging.