Marsupial immune genes, including cytokines, Natural Killer cell receptors and antimicrobial peptides, have been difficult to isolate due to the wide divergence of these genes from their eutherian counterparts. Early studies using conventional laboratory techniques only isolated the most conserved genes. With the sequencing of opossum and tammar wallaby genomes, many of these divergent genes have now been identified. Knowledge of these gene sequences will enable us to study immune function in marsupials. We can develop immunological reagents for studying the immune system of healthy marsupials and look at the immune response of diseased marsupials. We can also investigate marsupial specific immune functions such as the immune protection of pouch young. Additionally, antimicrobial therapies for both humans and marsupials may be designed around some of these immune peptides.