The RAPPER (Radiogenomics: Assessment of Polymorphisms for Predicting the Effects of Radiotherapy) study was formed in 2004 as a collaboration principally between clinicians and scientists in the Dept of Oncology in Cambridge (Neil Burnet, Gill Barnett, Charlotte Coles, Alison Dunning and Paul Pharoah) and at the University of Manchester (Rebecca Elliott and Catherine West). In late 2009 RAPPER became one of the founders of an international Radiogenomics Consortium, which has the goal of identifying genetic variants associated with toxicities resulting from radiotherapy. The main aim is to predict which cancer patients are most likely to develop radiation injuries from treatment with standard radiotherapy protocols and hence tailor the treatment to suit them. The second aim is to learn more about the molecular pathways responsible for radiation-induced tissue damage by identifying the responsible variants and genes at each locus discovered. The first GWAS being conducted within the Radiogenomics Consortium predominantly involves patients from the Cambridge IMRT Study as these have the appropriate material and collected data.