This is the third year of a three-year study. These investigators will be studying three molecular factors believed to be important in desmoid tumors: beta catenin, TCF-3 (a transcription factor) and ER-beta (an estrogen receptor). They are using a three-pronged approach. Aim 1 is the establishment of multiple desmoid tumor cell lines. Aim 2 is the examination of the role of beta catenin, TCF-3 and ERbeta interactions in desmoid proliferation using the cell lines developed in Aim 1. Aim 3 is the identification of desmoid tumor related molecular markers using oligoarrays and tissue microarrays.