Molecular genetics of the MHC.

Although some gaps remain, the major histocompatibility complex (MHC) has now been mapped in considerable detail in both humans and mice. From the results of DNA cloning and sequencing, there is now a detailed knowledge of which genes are expressed and the composition of the proteins encoded by them, as well as the structural basis of the polymorphism. The problem that can now be addressed is how the sequences of the polymorphic domains relate to the function of HLA molecules and to the diseases associated with the MHC.