In lymphoma there are multiple ongoing clinical trials examining the effectiveness of PD-1 blockade, and regulatory approval has been granted for anti-PD-1 therapy in primary mediastinal B-cell lymphoma (PMBCL) and classical Hodgkin Lymphoma (cHL) in the relapsed/refractory (R/R) setting. The gene discussed is PDCD1; the disease is classic Hodgkin lymphoma.