Because there was a correlation between CXCL13 and PD-1/PD-L1 gene expression (Supplemental Figure 5B), we hypothesized that CXCL13 had an adjuvant effect in HM-1 ovarian cancer models that were originally refractory to anti–PD-1/PD-L1 antibody therapy. This evidence concerns the gene PDCD1 and ovarian cancer.