The crucial role of the immunogenetic polymorphic system, HLA (Human Leukocyte Antigen), in susceptibility to sarcoidosis has been shown by some previous investigators enrolling mostly patients of North European descent (7, 9, 10); a previous study in a group of 114 Czech, i.e., Central European patients, was limited to a single class II (HLA-DRB1) locus (11). The gene discussed is HLA-DRB1; the disease is sarcoidosis.