HLA-DRB1 and pemphigus vulgaris: DSG3-specific T-cell clones derived from patients with pemphigus vulgaris are proliferated following co-culture with a B-lymphoblastoid cell line expressing HLA-DRB1*14:01, HLA-DQB1*05:03, and HLA-DRB1*04:02 (18–20) (Figure 1).