HLA-DRB1 and erythema multiforme: Given that neutralizing auto-Abs to IFN-γ appear to be exceedingly rare and that HLA-DRB1*15:02 and/or 16:02 alleles are strongly associated but not sufficient for their development, we hypothesized that patients with autoimmune conditions often observed among those harboring nAIGAs may also carry such autoantibodies, even in the absence of EM disease.