Figure 1.

Targeting recipient BM macrophages in HSC transplantation. During myeloablative treatment, most recipient BM cells are removed. A minor proportion of recipient HSC and EBI macrophages survive, proliferate after HSC transplant, and allow proper engraftment of donor HSCs and the expansion of donor-derived macrophages. Strategies aimed at expanding the populations of recipient macrophages, such as CSF1 treatment, are expected to facilitate HSC engraftment and ameliorate the recovery of patients subjected to radiotherapy and chemotherapy as well as HSC transplantation. BM = bone marrow, EBI = erythroblastic island, HSC = hematopoietic stem cell.