Yap is involved in combination treatment-induced apoptosis. MDA-MB-231 cells were transfected with Yap siRNA or control siRNA for 2 days and treated with combinations for 24 hours. Apoptosis was determined by annexin V/fluorescence-activated cell sorter (a). Western blot analyses were used to verify the knockdown efficiency of Yap siRNA and the effect of Yap siRNA on combination-induced poly(ADP-ribose) polymerase (PARP) cleavage, as well as p73 and p73-mediated death receptor 5 (DR5), Fas, Bax, Noxa and Bcl-2 (b). Data (a) expressed as mean ± standard deviation from three independent experiments; data in (b) representative of at least two independent experiments. *P <0.05, significantly different from control siRNA determined by t test. CDDP, cisplatin; DOXO, doxorubicin; GAPDH, glyceraldehyde-3-phosphate dehydrogenase.