IFNG and chlamydia trachomatis infectious disease: Even though a 300 fold increase in IL10 mRNA expression compared to a 60 fold increase in TNFα expression in koalas with chlamydial disease analysed in this study may be an indication of a similar role played by IL10 expression in koalas as well, a conclusive link can be established only after analysing the IFNγ expression in these animals.