In breast and ovarian cancer patients, the inhibition of the PI3K/AKT/MTOR pathway with PIK3R1 inhibitors (temsirolimus, ridaforolimus, everolimus) have been shown to satisfactory clinical outcomes of patients with endometrial cancer in Phase II trials (Slomovitz et al., 2010, 2015; Oza et al., 2011). This evidence concerns the gene PIK3R1 and endometrial cancer.