FACS analysis of cells from bone marrow, spleen and thymus showed that while the levels of thymic engraftment were equivalent, NOTCH1Mutated T-ALL LIC gave rise to a significantly higher CD34+ leukemic burden in the marrow and spleen of primary transplant recipients than NOTCH1WT T-ALL samples (Figures 2A and B; ***, P<0.001; Student’s t test). Here, CD34 is linked to acute lymphoblastic leukemia.