Paul has pursued academic research in DNA repair, drug development, cytometry and imaging technologies – in North America and the UK. He is Emeritus Professor of Cancer Biology at Cardiff University, a Director of MediWales, Past-President of The International Society for Advancement of Cytometry and panel chair for UK Research Councils. His inventions include anticancer drugs, molecular probes, imaging systems and biochips. He co-founded the award-winning start-up technology companies Biostatus Ltd and Oncotherics Ltd – the latter a new pharmaceutical company at the BioHub Alderley Park where he leads the development of hypoxia-activated pro-drugs from early-stage development through to cancer trials.