Patients with wild-type p53 and with low MDM2 inhibitor ex vivo cell kill IC50 values have more aggressive disease. Representative display of time-to-first-therapy (TTFT) estimates for 87 CLL cases with p53 wild-type immunoblotting pattern, using the Kaplan-Meier method, grouped by MDM2 inhibitor treatment. (A) MI-63 display of TTFT for groups below (green) and above (red) the median IC50 value. (B) Nutlin3 display of TTFT for groups below (green) and above (red) the median IC50 value. (C) MI-63 display of TTFT for quartiles of IC50 values (Q1-Q4, with Q1 lowest to Q4 highest). (D) Nutlin3 display of TTFT for quartiles of IC50 values (Q1-Q4, with Q1 lowest to Q4 highest).