The differences between these two types of EC are present also at a gene level, as microsatellite instability, RAS and PTEN (phosphatase and tensin homolog deleted on chromosome ten) mutations are associated with endometrioid EC and EH, while p53 mutations and abnormal accumulation are associated with serous carcinoma and intraepithelial cancers. The gene discussed is PTEN; the disease is serous adenocarcinoma.