As expected from [11], these primary xenografted cells were more aggressive than diagnostic cells as secondary transplant of 105 cells from CD7+/CD34+ xenografts generated leukemia as early as 12 weeks post-transplant compared to no leukemia development at the same time point when two times more sorted CD7+/CD34+ diagnostic cells had been transplanted (Figure 4A). This evidence concerns the gene CD7 and leukemia.