Breast cancer growth and spread is strongly influenced by the surrounding breast tissue - the extracellular matrix – or the mesh that holds cells together. In some breast cancers, large amounts of matrix are produced, which increases the aggressiveness of the cancer, reduces the effectiveness of chemotherapy, and results in poor survival rates. Using a recently uncovered drug we can target Peroxidasin and thereby slow down breast tumour growth and improve chemotherapy efficiency. This LYS-funded project will allow us to confirm our preliminary findings in support of our mission to generate the crucial data needed for the transition of our drug into clinical trials. It will also validate our Peroxidasin matrix signature, which we will be able to use to stratify patient tumour biopsies to rapidly identify those most likely to respond to our therapy. This offers a new way to personalise cancer treatment; by monitoring patient response to treatment for the purpose of making adjustments to achieve improved safety and efficacy, as well as significantly improving the fidelity of future clinical trials by knowing who to treat and when.