CD274 and ovarian carcinoma: Clinical trials of anti-PD-1 antibodies and anti-PD-L1 antibodies are currently underway, and early results suggest that anti-PD-1 antibodies alone may be effective in treating recurrent ovarian cancer, with PD-L1 expression strongly correlated with the efficacy of immune checkpoint blockade (ICB) therapy (Dai et al., 2018).