SPDL1 and ovarian cancer: For ovarian cancer, high sPD-L1 levels were significantly associated with poorer OS in both univariate (HR: 2.366; 95% CI: 1.179–4.750; p = 0.017) and multivariate (HR: 1.009; 95% CI: 1.000–1.018; p = 0.038) analyses, indicating that sPD-L1 is an independent prognostic factor.