A putative target epitope for effector T-cells in the processes suggested above ('epitope No. 2') was identified in a short peptide from the HERV-W env gene complex: MPVPSAPST. It is predicted that this peptide is presented, though only subdominantly, by diverse HLA class I molecules including Ld, A*0201, B*0702, B*5101, as determined by reference to the SYFPEIHI database for MHC ligands and peptide motifs [47] .