Retinoids decrease cell viability and induce caspase-3 cleavage in HCC cells. Huh-7 (A), HepG2 (B), and Hep3B cells (C)were incubated in serum-free medium containing individual retinoids (10 μM) for three days. Viable cells were counted and presented as a relative fold of DMSO treatment. Caspase-3 cleavage in detached cells was determined by Western blot. (* p < 0.05, ** p < 0.01 compared to DMSO treatment). Data were presented as mean ± S.E.M. Cells were counted in triplicates. Western blot results shown were representative results of two independent experiments.