Figure 2.

Growth and regression kinetics of the C4-HD tumor. The progestin-dependent C4-HD tumor was grown subcutaneously in 2-month-old virgin female nonovariectomized BALB/c mice until tumor size reached ∼100 mm². At this point, MPA depot was removed, and mice were further treated with E₂ or RU486 or remained untreated. Control animals were sham operated and treated with vehicle alone. As shown in the figure, complete regression is achieved in both the E₂- and RU486-treated groups after 15 days. Each curve represents the mean ± SD of three mice for each time point and treatment. The arrow indicates the beginning of the treatment.