Although there appeared to be early signs of hyperplasia and neoplasia, however, none of the animals developed visible ovarian or endometrial tumors within 8- to 10-months of age, suggesting that PTTG1 overexpression is not sufficient to induce tumorigenesis in mice and requires a hormonal trigger or cooperation of other gene(s), such as the inactivation of p53, to initiate tumorigenesis in OSE cells. This evidence concerns the gene PTTG1 and neoplasm.