title: Allelic polymorphism and complexity of the genes for HLA-DR beta-chains--direct analysis by DNA-DNA hybridization.
mesh_terms: D000483:Alleles; D004262:DNA Restriction Enzymes; D005796:Genes; D005802:Genes, MHC Class II; D006684:HLA-DR Antigens; D006801:Humans; D046911:Macromolecular Substances; D009693:Nucleic Acid Hybridization; D011110:Polymorphism, Genetic
chemical_list: D006684:HLA-DR Antigens; D046911:Macromolecular Substances; D004262:DNA Restriction Enzymes