Additionally, ARID1A, PIK3CA and PTEN alterations were significantly more common in endometrial cancer cases than in ovarian and cervical cancer cases (ARID1A: 29% vs 6% and 3%, p = 0.004; PIK3CA: 41% vs 12% and 9%, p = 0.009; PTEN: 59% vs 4% and 16%, p = 1.15E-07), whereas BRCA1 and BRCA2 somatic mutations were found only in patients with ovarian cancer. This evidence concerns the gene ARID1A and endometrial cancer.