LSCs are resistant to the effects of endosteal Dkk1 expression. (A) Kaplan-Meier survival curve demonstrating similar survival of WT recipients (solid line; median survival, 61 days, n = 6) compared with Dkk1 recipient mice (dashed line; median survival, 60 days, P = .36, n = 8) after injection with MLL-AF9-GMP–derived pre-LSCs. (B) Kaplan-Meier survival curve of recipient mice after the fourth round of leukemia transplantation. There was no difference in the survival of mice receiving AML that had been passaged through 4 generations of Dkk1 recipients (dashed line; median survival, 16 days, n = 5) to mice receiving AML that had been passaged through 4 generations of WT recipients (solid line; median survival, 16 days, P = .13, n = 5).