HLA-DPB1 and Allergy: However, although for example more than ten thousand T cell epitopes restricted by HLA-DR class II molecules have been reported (Immuno Epitope Database, IEDB; http://www.iedb.org/), a growing body of literature indicates that HLA-DP encodes fully functional molecules, restricting epitope responses in the context of cancer, allergy, and, of course, infectious diseases.