FIG. 6.

Tumor initiation and progression in progeny from p53^+/− Tax⁺ transgenic mice. Tax transgenic mice (solid lines) were mated with p53^−/− mice, and F₁ progeny (p53^+/− Tax⁺) were mated for production of F₂ progeny. (A) The percent tumor-free survival is plotted as a function of age. Animals were monitored weekly for tumor formation, morbidity, or spontaneous death over a period of 9 months. Except for p53^−/− Tax⁺ (n = 14) and p53^−/− (n = 5) mice, at least 20 mice were used for each comparison. The percent morbidity-free (development of fewer than four visible tumors; n < 3) survival (B) and the percentage of mortality-free mice (C) were measured from the time of initial tumor formation.