CD274 and ovarian carcinoma: The percentage of MO/MA with PD-L1 expression in peripheral blood of ovarian cancer was lower in low (I/II) and advanced (III/IV) stages (both p < 0.001) (Figure 6A), grade II (p < 0.0001) and grade III (p < 0.001; Figure 6B), and type I (p < 0.0001) and type II of OC (p < 0.01; Figure 6C) compared to healthy women.