Competitive transplantation of TIMP-1^−/− BM cells into WT recipients. (A) Schematic representation of the experimental model used for competitive transplantations of WT or TIMP-1^−/− BM cells into WT recipients. (B) Percentage of engraftment at 4, 8, and 12 weeks after transplantation, calculated as relative PB chimerism of donor CD45.2 cells. (C) Repopulation units at 12 weeks after transplantation, calculated according to Harrison²⁰  (see “Transplantation assays”). (D) Percentage of donor-derived (CD45.2) progenitors in the BM KSL compartment at 12 weeks after transplantation. Results are reported as mean ± SEM. *P < .05 and ***P < .001.