This programme has established a Molecular Therapy group to develop and validate PET imaging methodologies in pre-clinical disease models and humans. We are using cancer as disease model with which to assess the pharmacology of imaging agents. The initial focus is on the assessment of gene expression, and anti-proliferative activity of gene directed therapies, viral and non-viral. The human sodium iodide symporter reporter gene (hNIS) system together with Na[124I as well as bioluminescence methods are being explored to establish viral delivery. Furthermore, the biological activity of novel anti-cancer therapies are being examined for inhibition of proliferation in tumours (with [18F]fluorothymidine). Another area of interest is assessing mechanisms of action including induction of inflammation (with [11C]PK11195), pathway specific-imaging for mitogen activated protein kinase activity and angiogenesis. We aim to determine whether these radiotracers measure the biological processes for which they are intended to measure in an accurate, quantitative and reproducible manner. Although the studies will be done in cancer patients, the technologies should be widely applicable to other clinical areas of research; cancer offers a unique way of validating the radiotracers. The research outcomes will be published to enable use by scientists in academia and industry. The methods will play a major role in translation research programmes to develop new therapeutics and hence should have commercial and collaborative potential. We will iterate the pre-clinical and clinical programmes in a unique way to enhance the scientific value of the programme.