PDCD1 and ovarian serous cystadenocarcinoma: The expression of PD-1 was positively correlated with patients’ OS in BRCA, HNSC, Ovarian Serous Cystadenocarcinoma (OV), SKCM, and UCEC, while the PD-1 expression and patients’ OS were negatively associated in ESCA, KIRC, KIRP, LAML, LGG, and UVM (Fig. 5).