Prof Garth Powis talks to ecancertv at the 2010 San Antonio Breast Cancer Symposium about how causing stress to tumours by increasing hypoxia to reduce tumour resistance to chemotherapy and radiotherapy. Increase in glycolytic enzymes stimulates hypoxia (decreased blood flow to tumour). Increased hedgehog signalling produces desmoplasia (fibrosis of tumours) which can also stimulate hypoxia and start a cycle of further increased hedgehog signalling. This cycle can potentially be jump started using HIF inhibitors (in this case PX-478).