Investigators have developed genetic technologies that allow them to measure ITH in solid tumours and they now want to apply these to patients with prostate cancer to define the extent and the clinical importance of ITH in this disease which is currently unknown. This will involve looking at the control of genes in the cancer cells which make some tumours more aggressive than others. This may help in predicting which tumours are important and need to be targeted and those that could be left so that too much tissue damage does not occur as a result of therapy. Finding out why some cancer cells spread and others do not may also help to identify novel molecular targets that could be used to prevent the development of metastases.