Abstract: We identified regions of the HIV-1 proteome with high conservation, and low variant incidence. Such highly conserved sequences have direct relevance to the development of new-generation vaccines and diagnostic applications. The immune relevance of these sequences was assessed by their correlation to previously reported human T-cell epitopes and to recently identified human HIV-1 T-cell epitopes (identified using HLA transgenic mice). We identified (a) sequences specific to HIV-1 with no shared identity to other viruses and organisms, and (b) sequences that are specific to primate lentivirus group, with multiclade HIV-1 conservation.