HLA-DQA1 (Human Leukocyte Antigen DQ Alpha 1 Chain): HLA-DQA1 is a crucial part of the MHC class II molecule complex. It plays a vital role in the immune system by presenting peptide antigens to CD4+ T cells. This function is essential for initiating the adaptive immune response against pathogens. Variations in the HLA-DQA1 gene are associated with susceptibility to autoimmune diseases such as type 1 diabetes and celiac disease, underscoring its significance in immune regulation and disease risk.