Genotyping of commercial sex workers whose data previously demonstrated a correlation between Chsp60 antibody and risk of chlamydia PID identified DRB1, DQA1, and DQB1 alleles were predominant in this population; HLA DQA1*0401/DQB1*0402 heterodimer was associated with increased Chsp60 antibodies [19]. The gene discussed is HLA-DQA1; the disease is chlamydia trachomatis infectious disease.