Our goals in these studies are to attempt to determine whether there are markers in tumor tissue or blood that could be used to predict patient response to radiotherapy. One approach has been on the characterization of miRNA in tumors where patient outcome is known to determine whether there are miRNA that may be predictive of therapeutic response. Our more recent approaches include developing methods to track the presence of the HPV virus in HPV positive head and neck (H&N) patients as a measure of therapeutic response, but also as an early indicator of disease recurrence. We have taken a different approach for HPV negative patients. In this cohort we are developing a rapid method to identify mutations associated with H&N cancer within circulating tumor DNA.