Every year, millions of cancer patients receive chemical compounds (chemotherapy) to eliminate rapidly dividing tumor cells. However, chemotherapy also affects healthy cells making treated patients vulnerable to lethal infections. These serious side effects are pronounced in the elderly, and new therapeutic options are urgently needed to alleviate them. In the proposed project, we will determine the precise parameters responsible for the reduced tolerance to chemotherapy. We will also investigate the role of selected treatments in improving the recovery of aged hematopoiesis. Our results may help to develop new strategies to improve the overall survival of elderly cancer patients.