Our study of adult DM and PM in a Chinese population demonstrated that the putative haplotype DRB1*07-DQA1*01-DQB1*02 and the DRB1*07 and DQA1*0104 alleles are associated with an increased risk of DM, while DRB1*03 is associated with a reduced risk of DM. The gene discussed is HLA-DRB1; the disease is dermatomyositis.