Impact of pharmacological ascorbate on tumor growth. Tumors were grown in the flanks of athymic mice to a volume of ≈50 ± 10 mm3, and treatment commenced with either ascorbate (4 g per kilogram of body weight) or osmotically equivalent saline by i.p. injection as indicated. Data (± SEM) show growth curves and final tumor weight with either saline (□) or ascorbate (■) treatments in mice bearing Ovcar5 (A and B), Pan02 (C and D) and 9L (E and F) tumors. P values were calculated by unpaired t-test: *, P < 0.01; **, P < 0.005; ***, P < 0.001.