hZAC induces apoptotic cell death. DNA laddering. SaOs-2 cells were transfected with different quantities of vector pRK5 plasmid (1,500 ng, lane 1) or encoding chloramphenicol acetyltransferase (1,500 ng, lane 2), mZac (50, 150, and 500 ng, for lanes 3–5, respectively), hZAC (500, 1,000, and 1,500 ng, for lanes 6–8, respectively), or p53 (100 ng, lane 9). This experiment is representative of three independent experiments.