Survival curves. Survival curves are given for mice that received transplants of BM cells transduced with ND13 (n = 23), GFP control (n = 8), Meis1 (n = 6), or ND13 plus Meis1 (n = 21) viruses. Mice that received transplants of ND13-N51S (n = 6) and ND13-N51S-Meis1–transduced BM cells (n = 3) remained healthy (data not shown). Shaded box indicates the range of survival time for secondary transplant recipients of cells recovered from leukemic ND13-Meis1 primary mice. Two diseased ND13 mice that died 398 and 410 days after transplantation are not represented on this survival curve.