For instance, it has been demonstrated that epithelial specific deletion of Pten using Ltf‐driven Cre expression a causes endometrial hyperplasia whereas Pten ablation in stromal and epithelial cells using the Pgr‐driven Cre expression[20] leads to invasive endometrial carcinomas.[29] These results strongly suggest that Pten deletion in endometrial stromal cells is likely to affect epithelial cell tumor progression. The gene discussed is PGR; the disease is endometrial carcinoma.