Relapse-free and event-free survival of T-ALL patients in three different Notch pathway activity groups. Three different Notch pathway activity groups were separated based on the lowest 25% Notch pathway activity (blue line), the highest 25% Notch pathway activity (red line), and the remaining 50%, termed the ‘middle’, Notch pathway activity (orange line). Relapse-free (A) and event-free (B) survival is plotted for the T-ALL pediatric patients treated on the DCOG ALL-7, -8 and -9 and COALL-97 protocols. p = NS (not significant) (A) and p < 0.05 (B) (log-rank test). Events include relapse, non-responsiveness to induction or maintenance therapy, change of treatment or death due to infection, toxicity or other causes.