CTLA4 and ovarian benign neoplasm: Compared to patients with benign ovarian tumors and healthy controls, OC patients had an increased CD8+ Treg cell subset with increased expression of CD25, CTLA-4, and Foxp3 and decreased expression of CD28, whereas CD8+ Treg cells induced in vitro by co-culture with OC cells similarly showed increased expression of CTLA-4 and Foxp3 and decreased expression of CD28 [142].