This study agrees with a smaller HLA sequencing study12 in 1597 PD cases and 1606 controls which also observed a protective effect of DRB1*04 and the same amino acids, although it also reported additional associations with DRB1*01:01 and DRB1*10:01 which were not confirmed in the current study. Here, HLA-DRB1 is linked to Parkinson disease.