A unique feature of the immunodominant IE1 peptide is its presentation pattern on MHC class I. During the α phase of infection, the immunodominant IE1 peptide YPHFMPTNL is presented to CTLs on H-2Ld -isotype MHC class I. However, during the β phase of infection, immune evasion proteins encoded in the MCMV genome prevent the export of H-2Ld from the endoplasmic reticulum, diminishing the presentation of the IE1-derived peptide (49, 50). This evidence concerns the gene HLA-C and infection.