E-cadherin belongs to a class of proteins called 'tumour suppressors' that provide normal cells with a degree of protection against cancer development. However, inactivation of the gene that encodes E-cadherin (CDH1) is frequently seen in tumours, leading to an increase in the tumour's ability to survive and invade other tissues. We propose that the loss of E-cadherin creates vulnerabilities in the tumour cell that could be targeted with drugs. In this project we will systematically search for proteins which, if inactivated, lead to the death of cancer cells lacking E-cadherin, but not cells with normal levels of E-cadherin. We will then conduct a screen to identify drugs active against these alternative targets. We predict that these new drugs will be highly active against many common tumour types and will produce fewer side effects than standard chemotherapies.