Chromosome 9p24.1 amplification and increased expression of PD-1 ligands in HL and MLBCL cell lines. (A left) Smoothed chromosome 9p gene copy number estimates for each DLBCL, MLBCL, and HL cell line. The color scale ranges from blue (deletion) to red (amplification). (Right) GISTIC Q values (for all cell lines) for the 9p24.1 amplification that includes the PD-L1/PD-L2 loci. (B) PD-L1 and PD-L2 transcript abundance in the DLBCL, MLBCL, and HL cell lines was assessed by transcriptional profiling and represented in box plots.