HLA-A is a major histocompatibility complex class I molecule essential for adaptive and innate immunity. It functions primarily as a peptide-presenting protein that displays antigenic epitopes on cell surfaces for recognition by CD8+ T cells 1. HLA-A achieves this through assembly with beta-2-microglobulin and processed peptide antigens, forming stable complexes that bind CD8 receptors on T lymphocytes 2. The mechanism involves loading peptides derived from viral, bacterial, or self-antigens into the peptide-binding groove, enabling both TAP-dependent and TAP-independent antigen processing pathways 3. Specific HLA-A alleles demonstrate clinical relevance in infectious disease control. For example, HLA-A*1101 restricts CD8+ T cell responses against human cytomegalovirus, enabling tetramer-based detection of virus-specific immunity 1. HLA-A*0201-based recombinant constructs elicit CD8+ T cell proliferation and have been evaluated as potential HIV vaccine candidates 2. The considerable allelic diversity of HLA-A, including newly identified variants 456, underlies population-level variation in immunological responses and disease susceptibility. Molecular typing methods are essential for accurate HLA-A characterization in clinical and research contexts 3.