It is well characterized that in more than 85% of classic HLs, tumor (Hodgkin's/Reed Sternberg) cells overexpress PD-L1 and PD-L2 due to a genetic mutation in 9p24, as observed in primary mediastinal B cell lymphoma [23]. The gene discussed is PDCD1LG2; the disease is B-cell non-Hodgkin lymphoma.