In cluster 2, the significantly enriched genes were HLA-B, HLA-A, HLA-DRB1, HLA-DQA1 and HLA-DQB1, with all genes related to allograft rejection, GVHD, type I diabetes, autoimmune thyroid disease and viral myocarditis. The gene discussed is HLA-DQA1; the disease is viral myocarditis.