ARID1A and ovarian serous tumor: AT-rich interaction domain 1A (ARID1A) and phosphatidylinositol-4,5-3-kinase catalytic subunit alpha (PIK3CA) mutations characterize a majority of ovarian clear-cell carcinomas [4,5,9,10], while low-grade serous ovarian tumors predominantly show alterations in KRAS [5,11,12,13,14,15].