Among the cHL patients in our cohort, 3 patients received anti-PD-1 mAb treatment. Tumor cells in 2 patients harbored MHC-II expression accompanied by CD4+ T-cell infiltration, and anti-PD-1 mAb monotherapy showed remarkable clinical benefits in both patients...Patient CCC-43 (64-year-old male) received nivolumab monotherapy as fourth-line therapy. He achieved a partial response after 8 cycles of nivolumab...Patient CCC-66 (56-year-old male) received nivolumab monotherapy as fourth-line therapy and achieved a PR after 8 cycles of nivolumab.