To assess whether the loss of PDCD4 promotes or suppresses hepatoma cell growth, HepG2 (wild-type p53), Huh7 (mutant p53 and p16-deficient) and Hep3B (p53- and Rb-deficient) hepatoma cells were treated with three types of PDCD4-specific siRNAs (p1, p2, and k603). The gene discussed is TP53; the disease is hepatocellular carcinoma.