When we measured the production of hydrogen peroxide in two rat endometrial tumor cell lines with loss of expression of Gpx3 and in one premalignant/normal endometrial cell line with normal Gpx3 expression, we found that a higher generation of hydrogen peroxide was produced in the tumor cell lines than in the premalignant cell line (Figure 3). This evidence concerns the gene GPX3 and endometrium neoplasm.