The heterogenous impact of p53 on extrinsic cell death induction in xenografted ALL cells. A) Patient-derived ALL-10S (left panel), ALL-54 (central panel) and ALL-177 (right panel) cells transfected with siRNA against p53 (sip53) or a control sequence (sicontrol) were stimulated with TRAIL (100 ng/ml) for 24 hours. Knockdown-efficiency of p53 by RNA interference is presented in Additional file 1: Figure S4. B) Cells from n = 11 different xenograft samples with wildtype p53 status (from Figure 4A and data not shown) were classified as in Figure 3B. C) Patient-derived ALL cells from Figure 4B were separated by the type of leukemia, the state of disease and the TRAIL sensitivity in the presence of p53 as in Figure 3C. D) Patient-derived ALL cells from Figure 4B were analyzed for the relative p53 content as in Figure 3D. Cell death induction, calculation of specific apoptosis, presentation of data and statistical analysis were performed as in Figure 3. *p < 0,05, paired t-test. NS = statistically not significant.