Effect of different doses of MP, PGE1 MZ, and MPA on DNA synthesis in hepatocytes cultured in the presence of EGF (10 ng/mL). In some experiments, MP was tested in the absence of insulin, and PGE1 in the absence of EGF. N = 9 for all data points, which represent three experiments with triplicate determinations. Data expressed as mean ± SD. *P <.05; **P <.01.