<p>Major Histo Compatibility Complex (MHC) mapped to locate in the short arm of the chromosome 6 of the human being, contains a group of genes that code for proteins (antigens) expressed in a variety of cell types known as Human Leukocyte Antigens or HLA. This MHC/HLA system is involved in the immune system. It is a highly polymorphic DNA ( Deoxy Ribo Nucleic Acid) system : the very reason for its use in forensic crime and paternity work in addition to detect tissue compatibility in transplants.</p>