The aim of MHC Protocols is to document protocols that can be used for the analysis of genetic variation within the human major histocompatibility complex (MHC; HLA region). The human MHC encompasses approximately 4 million base pairs on the short arm of chromosome 6 at cytogenetic location 6p21. 3. The region is divided into three subregions. The telomeric class I region contains the genes that encode the HLA class I molecules HLA-A, -B, and -C. The centromeric class II region contains the genes encoding the HLA class II molecules HLA-DR, -DQ, and -DP. In between is the class III region,...