HLA-DRB1 and ependymoma: For instance, the A*02:01-B*44:02-C*05:01 haplotype was overrepresented particularly in three cohorts (neuroblastoma MYCN-A, ependymoma, aRMS), whereas three DRB1-DQA1-DQB1 haplotypes (*15:01-*01:02-*06:02, *03:01-*05:01-*02:01, and *07:01-*02:01-*02:02) showed discordant frequencies across multiple tumor types and subtypes.