Percentage of cell proliferation rate. TDH inhibited EC9706 cells proliferation in a dose- and time-dependent manner. Human esophageal cancer EC9706 cells were seeded in 96-well plates and treated with various concentrations of TDH for 24 and 48 h; TDH was diluted in the RPMI1640 medium. Data were expressed as mean ± standard error. Six samples were tested on each treatment. The experiment was repeated three times.