CD274 and ovarian cancer: PD-L1 mRNA expression was significantly linked to worse PFS in 1228 patients with ovarian cancer (227458_at: HR = 1.55, 95% CI = 1.28–1.88, P < 0.001; 223834_at: HR = 1.41, 95% CI = 1.14–1.75, P = 0.0015).