Such haplotype is in strong linkage disequilibrium with the HLA-A*02:01:01:01 allele, which led the authors to conclude that combined qualitative (i.e., the presence of HLA-A*02:01 specificity) and quantitative (a higher HLA-A mRNA expression) effects are involved in vitiligo risk [13]. The gene discussed is HLA-A; the disease is vitiligo.