Peripheral blood samples will be taken with informed consent from patients undergoing standard radiotherapy before and during treatment for breast, lung, gastrointestinal and genitourinary tumours. Responses from panels of up to 800 coding and non-coding RNAs will be assessed in the samples using the nCounter system. Candidate genes identified by PHE, Columbia and/or in the literature as being specific to radiation responses will be included, together with genes relevant to systemic inflammatory responses, to identify transcriptional responses for a range of doses and exposures on an inter-individual basis. Data will be analysed using existing and new statistical tools focused on count data modelling. The intended outcome is identification of a radiation specific panel of genes to inform individual radiation responses and if the results are favourable, a large scale follow up to this proposed pilot is expected in due course.