Coupling of TgPTTG with mutant p53 led us to conclude that the early neoplastic events (normal to dysplastic) were independent of p53 as the additional mutation did not enhance incidence of ovarian cancer; however overexpression of PTTG and loss of p53 function reduced the time of development of certain cancers, including sarcoma. The gene discussed is TP53; the disease is sarcoma.