MYCN and neuroblastoma: The DRB1*03:01-DQA1*05:01-DQB1*02:01 haplotype was underrepresented in eRMS, aRMS, nephroblastoma and ependymoma (freq 0.021 to 0.056, RA 0.18 to 0.48) but overrepresented in neuroblastoma MYCN-A (freq 0.192, RA 1.65).