Some studies have found that the major molecular alterations of EBOT include alterations of the CTNNB1 gene (50%), and the PTEN gene (20%), as well as microsatellite instability (50%), which are also observed in uterine endometrioid carcinoma, supporting the hypothesis that endometriosis may be a precursor to EBOT. The gene discussed is PTEN; the disease is endometrial endometrioid adenocarcinoma.