Many studies have investigated ARID1A mutations as prognostic markers in a multitude of different cancers, such as OCCC, as well as breast, gastric and bladder cancer [91,93,97,100,102,155,159–161], but to date, none have demonstrated a consistent prognostic significance of ARID1A mutational or expressional status. The gene discussed is ARID1A; the disease is urinary bladder cancer.