Both Interleukin-6 (IL-6) and Interferon gamma (IFN-γ) are among those cytokines that are involved in the determination of the Type 1 or Type 2 dominant T-cell response to mycobacterial infection. These responses determine the localisation or dissemination of infection through the formation and maintenance of the granuloma. It has been suggested that deficiencies in this response may be responsible for the apparent susceptibility of Australian macropods to atypical mycobacteria. To investigate this, we have characterised the complete IL-6 and IFN-γ expressed gene sequences and predicted protein properties for the model Macropod, the Tammar wallaby (Macropus eugenii). Further to this, we have identified these gene sequences in an endangered macropod (Rufous Hare-wallaby, Lagorchestes hirsutus), which is known to be affected by atypical mycobacterial disease. The characteristics and tissue-expression of T-cell modulating cytokines in marsupials, with particular reference to immunopathology associated with mycobacterial infection, will be presented.