HLA A*0201

The major histocompatibility complex (MHC) is the most polygenic and polymorphic region in the human genome. Human leukocyte antigens (HLA) Class I include HLA-A, -B and -C loci. HLA-A are encoded by the HLA-A locus on human chromosome 6p. The HLA genes constitute a large subset of the MHC of humans. HLA-A is a component of certain MHC class I cell surface receptor glycoproteins that resides on the surface of all nucleated cells and platelets. Class I MHC molecules bind peptides generated mainly from degradation of cytosolic proteins by the proteasome and display intracellular proteins to cytotoxic T cells. However, class I MHC can also present peptides generated from exogenous proteins, in a process known as cross-presentation. Alternatively, class I MHC itself can serve as an inhibitory ligand for natural killer cells (NKs).