Abstract: The present invention provides methods for identifying polynucleotide and polypeptide sequences in human and/or non-human primates which may be associated with a physiological condition, such as disease (including susceptibility (human) or resistance (chimpanzee) to development of AIDS). The methods employ comparison of human and non-human primate sequences using statistical methods. Sequences thus identified may be useful as host therapeutic targets and/or in screening assays.