HLA-DRB1 and infection: In a study to analyze HLA-DRB1, DQA1 and DQB1 allelic polymorphism in Iranian patients with pulmonary TB, HLA-DRB1*07 and HLA-DQA1*0101 alleles apparently conferred susceptibility to TB while HLA-DQA*0301 and HLA-DQA*0501 conferred protection against this infection [34].