Effect of p53 on CLL development in IgH.TEμ and IgH.T mice. (A) Kaplan-Meier survival curve of IgH.TEμ (black, n = 31), IgH.TEμ/p53^−/− (red, n = 6), and p53^−/− (blue, n = 9) mice. (B) Kaplan-Meier survival curve in IgH.T (black, n = 15), IgH.T/p53^−/− (red, n = 10), and p53^−/− (blue, n = 9) mice. Tumor-free survival is plotted over time.