As shown in Fig. 10c and d, the expression of Bax of A549 cells transfected by p21 siRNA was decreased after treatment of CDDP alone or AKBA plus CDDP compared with A549 cells transfected by NC siRNA, suggesting that knockdown of p21 decreased the percentages of apoptotic cells and these two drugs exerted anti-cancer effects via p21-depdent signaling pathway. The gene discussed is BAX; the disease is cancer.