Preliminary studies of salmon EST03G12 undertaken within FRDC Project #2004/218 did not determine whether it encodes a functional protein and therefore it's biological role in AGD pathology remains largely unknown. However, some evidence was obtained that it might function as either a negative regulator of the innate immune response or a transcriptional factor driving the hyperproliferation of gill cells observed at sites of AGD lesions. Thus it might play a significant role in the development of AGD pathology and in progress the disease. Indeed, if EST03G12 expression impacts negatively on the innate immune response against AGD, it is an obvious target for intervention strategies. However, in order to devise such strategies there is a need to better characterise the EST to examine whether it encodes a functional protein, it's role during the progress of AGD and whether allelic differences in the gene sequence and/or its promoter amongst salmon correlate with differences in their resistance/susceptibility to AGD.