Cancer is the largest cause of death in New Zealand and is very often treated by chemotherapy. Unfortunately, this treatment method kills cells throughout the entire body, often has a low success rate and a large number of severe side effects, such as sterility. Therefore, more cancer-specific therapies are needed; a better understanding of the underlying tumour biology is essential for development for these so-called targeted therapies. We recently discovered that the protein AhR is a major contributor to tumour formation, however, the underlying mechanism is totally unclear. In this project, we will elucidate the contribution of AhR to tumour growth by investigating the molecular mechanism of action. The understanding of this pathway can be used to increase the efficiency of targeted tumour therapies.