Human Leukocyte Antigen (HLA) 
(En español)
A group of molecules found on the surface of almost every cell in the body. Human leukocyte antigens (HLAs) present protein fragments (peptides) to immune cells. If the cells recognize the peptides as foreign, the body mounts an immune response. Some diseases and drug reactions are linked to certain types of HLAs.
See Related Term(s): Major Histocompatibility Complex