 Type I and type II uterine tumors also appear to have a different pattern of molecular alterations that underlie pathogenesis andor progression 1. Alterations in the tumor suppressor gene PTEN, microsatellite instability, and K-ras alterations have been associated with the early development of type I tumors, while these alterations are uncommon in type II cancers. On the other hand, mutations in the TP53 gene appear to be important in the early pathogenesis of uterine serous carcinomas. Moreover, HER2 overexpressionamplification has been associated with type II tumors. 