Immunotherapeutic approaches hold promise in lymphoma treatment, as demonstrated by the great success of chimeric antigen receptor (CAR) T cell therapies in relapsed/refractory DLBCL and the approval of programmed cell death protein 1 (PD-1) blockade in relapsed/refractory Hodgkin lymphoma and primary mediastinal large B-cell lymphoma (5–9). Here, PDCD1 is linked to lymphoma.