CTLA4 and ovarian cancer: Furthermore, the survival analyses of patients with ovarian cancer clearly indicated that the expression levels of PD-1/PD-L1/CTLA-4 had no significant influence on overall survival (OS) (Figures 1D–F), and PD-1/CTLA-4 had significant influence on disease-free survival (DFS) while PD-L1 had nonsignificant (Figures 1G,I).