Interestingly, ARID1A mutations frequently co-occur with PIK3CA or PTEN mutations in human tumors, and double mutations of Arid1a with Pten or Pik3ca result in ovarian tumor formation in mice [35, 36] suggesting a cooperative carcinogenic role of PI3K and chromatin remodeling pathways. The gene discussed is PTEN; the disease is ovarian neoplasm.