HLA-DPB1 and glioblastoma: In HGG, homozygosity at HLA-B was not observed in both GBM and non-GBM cases but was common at DPA1-DPB1 (17.4 and 24.1%, respectively), whereas homozygosity frequencies at ≥ three HLA class II loci, DQA1-DQB1, and DQB1 alone were slightly higher in non-GBM (13.8 to 10.3%) than GBM cases (none to 4.3%) (Figures 4A, B; Supplementary Table S8).