Structural variants at 9p24.1 (affecting CD274/PD-L1 and PDCD1LG2/PD-L2, with copy number gains in 67% of cases and chromosomal translocations in 13% of cases) and at 6p21.32 (heterozygous deletions, harboring the MHC class II encoding genes HLA-DRB, HLA-DQA, HLA-DQB) may contribute to TME of PCNSL [24,43]. The gene discussed is PDCD1LG2; the disease is primary central nervous system lymphoma.