Impact of the BMME on survival and leukemia. (A) Schematic of transplants into WT recipients. (B) In WT recipients, survival curves indicate mitigation of progression to leukemia or death. Data collected from 8 separate experiments. Log-rank (Mantel-Cox) test: P = .98. The BM age demarcated on the x-axis is indicative of primary donor BM age based on date of birth of the primary donor. No leukemia was diagnosed in these groups. (C) Schematic of competitive repopulation assay in which marrow from an NHD13 mouse was competitively transplanted into either irradiated NHD13 or WT recipients. (D) Survival curves showing progression to leukemia or death in primary WT recipients of competitively transplanted NHD13 marrow and in primary NHD13 recipients of competitively transplanted NHD13 marrow. Data collected from 6 separate experiments. Leukemia was formally diagnosed in 1 WT recipient and 4 NHD13 recipients. The same donor/competitor ratios were present in both experimental groups. Log-rank (Mantel-Cox) test: P = .01. In all transplants, competitor marrow was 6- to 8-week-old WT marrow. The BM age demarcated on the x-axis is indicative of primary donor BM age based on date of birth of the primary donor.