HSCs and TBI dose titration. (A) Percent engraftment of NOD mice given 4000, 5000, or 10 000 B6 HSCs and conditioned with 950 or 1050 cGy of TBI. (B) Percentage of donor chimerism in engrafted NOD recipient mice. (C-D) Survival of NOD recipients conditioned with 950 or 1050 cGy of TBI and transplanted with various B6 HSC doses in an allogeneic model (B6 → NOD). Results are from 3-5 separate transplant experiments.