Interestingly, LR-CHL cases showed fewer copy number amplifications of CD274/PDCD1LG2 (19%, 5/26 cases) compared to other CHL subtypes (43%, 9/21 cases), and CD274 copy number amplification status was positively correlated with PD-L1 protein expression on HRS cells (Fig. 5D). This evidence concerns the gene CD274 and classic Hodgkin lymphoma.