NOTCH1 and acute lymphoblastic leukemia: Consistent with previous observations on the correlation between the signaling strength of various Notch1 mutants and T-ALL activity [25], we noted that GFPhigh DP cells, but not the GFPlow DP cells, isolated from ICN1:181ab1+/+ T-ALL mice 2 weeks after transplantation caused T-ALL in secondary recipients (Figure 3I).