<unk> , or tissue compatibility, is the property of<unk> aving the same, or sufficiently similar, alleles of a set of genes called<unk> uman leukocyte antigens <unk> LA), or major<unk>  complex (MHC). Each individual expresses many unique<unk> LA proteins on the surface of their cells, which signal to the immune system whether a cell is part of the self or an invading organism. T cells recognize foreign<unk> LA molecules and trigger an immune response to destroy the foreign cells.<unk>  testing is most relevant for topics related to whole organ, tissue, or stem cell transplants, where the similarity or difference between the donor's<unk> LA alleles and the recipient's triggers the immune system to reject the transplant. The wide variety of potential<unk> LA alleles lead to unique combinations in individuals and make matching difficult.
Histocompatibility
Tissue tropism
Antigenicity
Immunity 
Immune response
Bioprocess
Immune privilege
Thermostability