CD274 and classic Hodgkin lymphoma: For Roemer et al. PD-L1/PD-L2 alterations are a defining feature of cHL, 97% of the patients had concordant alterations of the PD-L1 and PD-L2 loci (including polysomy, copy gain and amplification) and this amplification was connected to a short PFS and a more advanced stage of disease [115].