PD-1 signaling in mice has also been reported to inhibit NF-κB, a crucial signaling molecule involved in the maturation and activation of DCs.124 Similarly, PD-1+ DCs were also observed in human ovarian cancer, as determined by flow cytometry.28 Similar to its role in murine species, PD-1 expression on human DCs suppresses NF-κB-dependent cytokine release in a SHP-2-dependent manner. This evidence concerns the gene PDCD1 and ovarian cancer.