Microenvironmental effects TIMP-1 deficiency on engraftment. (A) Schematic representation of the experimental model used, consisting of transplanting WT BM cells into either WT or TIMP-1^−/− animals. (B) Percentage of engraftment at 3, 6, and 9 weeks after transplantation, calculated as relative PB chimerism of donor CD45.1 cells. (C) Lineage distribution of Mac-1⁺ myeloid cells, B220⁺ B lymphocytes, and CD4⁺CD8⁺ T lymphocytes in the PB of animals that received a transplant at 6 weeks. Results are percentages of the donor-derived white cell CD45.1 subset. (D) Percentages of circulating KLS cells in the PB of WT and TIMP-1^−/− mice. Results are reported as mean ± SEM.