We observed significantly shortened progression-free survival (PFS) (5-y PFS 71% vs. 92%; P = 0.032) and overall survival (OS) (5-y OS 89% vs. 100%; P = 0.01) in patients with high levels of CD4+PD-1+CXCL13+ T cells in LR-CHL (Fig. 6 E and F and SI Appendix, Table S5). Here, PDCD1 is linked to classic Hodgkin lymphoma.