Selection of target genes for delivery to cane toads has focused on metamorphosis since it is a critical phase in the amphibian life cycle. Metamorphosis is characterised by rapid and extensive morphological changes [12, 13] , accompanied by strong shifts in the expression of genes and proteins at the molecular level [14, 15] . Cane toad genes that are expressed in metamorphs but not in tadpoles therefore represent ideal targets to block and thus manipulate aspects of development. One documented example of the transition from a larval to an adult form in amphibians is haemoglobin [16] and we have used microarray analysis to establish that adult haemoglobin is significantly upregulated during cane toad metamorphosis [17] . Injecting tadpoles with adult globin interfered with expression of this protein in Rana catesbeiana, and induced changes in gene expression profiles of metamorphs [18] . Thus we hypothesise that it may be possible to alter metamorphosis by immunologically sensitising larval stages (tadpoles) to proteins expressed only in later post-metamorphic stages. Adult globin is not a cane toad specific gene; we used it here to determine whether autoimmunity might affect the protein profile of metamorphs. If successful, the concept would be extended to cane toad specific genes that were upregulated at metamorphosis.