hla definition
The human leukocyte antigen (HLA) system is the locus of genes that encode for proteins on the surface of cells that are responsible for regulation of the immune system in humans.he HLA genes are the human versions of the major histocompatibility complex (MHC) genes that are found in most vertebrates (and thus are the most studied of the MHC genes). The proteins encoded by certain genes are also known as antigens, as a result of their historic discovery as factors in organ transplants.