HER2 Current testing methods (FISH is considered the gold standard) aren't accurate enough and better tests are definitely needed. Furthermore, we do not fully understand the link between HER2 gene copy number (which is what FISH is testing for) and Herceptin treatment since less than 50% of HER2+ metastatic breast tumors respond to Herceptin monotherapy and some HER2- do respond. So, better tests (in sequence we trust!) and their clinical relevance as well.