PD-L1 and PD-L2 genetic alterations and aberrant expression of PD-L1 protein in IVLBCL. (A) Distributions and types of SVs involving PD-L1 (CD274) and PD-L2 (PDCD1LG2) are depicted. (B) CNAs of PD-L1 and PD-L2 in 2 patients with IVLBCL, IVL_02 and IVL_11. (C) Novel translocation involving PDCD1LG2 identified in IVLBCL (IVL_05). (D) Number of somatic mutations in patients with and without SVs/CNAs in PD-L1/PD-L2. Box-and-whisker plots show the boxes indicating median and interquartile range, and the whiskers denoting the range. The overlaid points are the observed mutation burden of individual samples. (E) PD-L1 protein expression with IHC analyses using 3 different anti–PD-L1 antibodies: 28-8, E1J2J, and SP142. Skin biopsy samples (IVL_14), BM clot section samples (IVL_07, 12, and 18), and lung biopsy samples (IVL_02) were used for IHC analysis. Hematoxylin and eosin stain; original magnification ×400. AsCN, allele-specific copy number; CN, copy number; DRT, disruption; EC, extracellular domain.