Lymphoma B cells from ABC DLBCL strongly express PD-L1. (A) Representative histograms of PD-L1 and PD-L2 expression on isotype-restricted clonal B cells, except for cHL (top), and percentage of B cells expressing PD-L1 or PD-L2 in DLBCL (n = 23), FL (n = 15), cHL (n = 10), and rLN (n = 7) samples (bottom). (B) Percentage of PD-L1⁺ lymphoma cells in GC DLBCL (n = 9), ABC DLBCL (n = 12), and FL (n = 15) samples. *P < .05, **P < .01, ***P < .001 by Mann-Whitney nonparametric U test.