Effect of MyD88 silencing on p53-dependent tumor inhibition in vivo. A) Growth of HCT116 p53+/+ or p53–/– cells expressing doxycycline-inducible MyD88 short hairpin RNA (shMyD88) implanted subcutaneously in nude mice, treated or not treated with doxycycline. B) Hematoxylin and eosin (H&E; scale bar = 3mm), and TUNEL staining (scale bar = 100 μm) on tumor sections from mice described in (A). Inset, high magnification of the TUNEL staining in HCT116 p53+/+ tumors, showing nuclear staining. Each experiment was performed twice, with five mice per group. Error bars indicate standard deviation. For statistical analysis, one-sided Student t test was used, with P values indicated in the figure.