(UroToday.com) STAG2, part of cohesin, a complex involved in chromosome organization and DNA repair, has been described as a tumor suppressor gene in bladder cancer.1 While the mechanisms by which STAG2 contributes to bladder carcinogenesis have not been clearly elucidated, it has been proposed that they involve processes different from altered chromosome segregation. STAG2 inactivation is associated with differentiated, luminal tumors that are significantly enriched in the PPARg pathway, a driver of urothelial differentiation.