A genome-wide association study in Japanese patients with IgG4-RD (7) has identified the human leukocyte antigen (HLA)-DRB1 region as an IgG4-RD susceptibility locus and has shown significant associations of IgG4-RD manifestation with DRB1*04:06, DRB1*09:01, and DQB1*03:03. This evidence concerns the gene HLA-DRB1 and immunoglobulin G4-related sclerosing disease.