Statistical analyses

No statistical method was used to predetermine sample size. For in vitro experiments, a minimum of 3 patient samples were chosen as a sample size to ensure adequate power. Data obtained from each patient sample represents an independent experiment. For in vivo work, a minimum number of 2 mice per arm were used. The investigators were not blinded to allocation during experiments. Mice were allocated based on their pre-treatment engraftment levels and no method of randomization was used. All mice were cared for equally in an unbiased fashion by animal technicians and investigators. No animal was excluded from the analysis.

P values were calculated by two-tailed paired or unpaired Student’s t-test using GraphPad Prism software (GraphPad Software 5.0) as indicated in the figures legends. Where indicated, variables were transformed using the natural logarithms before t tests were performed to meet the assumption of equal variances.