HLA-DQA1 and celiac disease: The vast majority of celiac disease patients express human leukocyte antigen (HLA)-DQ2.5 (HLA-DQA1*05/HLA-DQB1*02, expressed by 90% of patients), and the remaining patients are either HLA-DQ8 (HLA-DQA1*03/HLA-DQB1*03:02) or HLA- DQ2.2 (HLA-DQA1*02:01/HLA-DQB1*02) [2, 3].