Several studies have demonstrated the association between Moyamoya disease (MMD), a progressive cerebrovascular disease with unknown etiology and allelic and haplotypic differences of HLA, including differences in both HLA class I and class II alleles (e.g., HLA-A*24, HLA-B*54, HLA-DRB1*04:05, *04:10, and HLA-DQB1*04:01) in multiple cohorts of East Asians (25–27), as well as in Europeans (28). Here, HLA-DQB1 is linked to cerebrovascular disorder.